RAW distinguish 'sunlight' from 'direct sunlight'
Vampires have (bold mine):
Sunlight Hypersensitivity. The vampire takes 20 radiant damage when it starts its turn in sunlight. While in sunlight, it has disadvantage on attack rolls and ability checks.
Many other monsters (including drow and kobold NPCs) have sunlight sensitivity, which does not include taking radiant damage, but which does include disadvantage when "in sunlight".
Drow and kobold (VGtM) PCs, on the other hand, have (second bold mine):
Sunlight Sensitivity. You have disadvantage on attack rolls and Wisdom (Perception) checks that rely on sight when you, the target of the attack, or whatever you are trying to perceive is in direct sunlight.
Myconids have (second and third bolds mine):
Sun Sickness. While in sunlight, the myconid has disadvantage on ability checks, attack rolls, and saving throws. The myconid dies if it spends more than 1 hour in direct sunlight.
From these examples, particularly that of the myconids, we can see that the rules distinguish between being in sunlight, and being in direct sunlight, with the second being a specific and more restrictive case of the first. We know that vampires are affected by the more general case, and thus their sunlight hypersensitivity is triggered not only by direct sunlight but by 'indirect' sunlight as well. We can take 'indirect' as synonymous with reflected or refracted sunlight, that is, any sunlight that arrives at the vampire without having a direct path (line of sight) to the sun. In the OP's list of cases, then, we know that vampires are vulnerable when (1) sunlight comes down from the sun and hits them directly [they are in direct sunlight], (2) sunlight bounces off a mirror (or several) and hits them [they are in sunlight], and (3) during the day, the vampire is under the shade of a tree but the area is not dark [they are in sunlight].
RAW darkness includes very dim light
The PHB, in its section on the Environment; Vision and Light, explains that:
The presence or absence of light in an environment creates three categories of illumination: bright light, dim light, and darkness.
Of the three, "Even gloomy days provide bright light", while:
An area of dim light is usually a boundary between a source of bright light, such as a torch, and surrounding darkness. The soft light of twilight and dawn also counts as dim light. A particularly brilliant full moon might bathe the land in dim light.
Finally:
Characters face darkness outdoors at night (even most moonlit nights), within the confines of an unlit dungeon or a subterranean vault, or in an area of magical darkness.
Even though, for the sake of rules simplicity, there are just three categories of lighting, we understand that light is a gradient or continuum. The brightest light will, with distance and intervening obstructions, eventually become dim light and then darkness. What we call 'darkness' is not necessarily the complete absence of light, but simply lighting that is too faint to call dim - most moonlit nights, and all moonless but starlit nights, are in 'darkness', despite the fact that there are clear sources of light visible from within them. Likewise, artificial sources of light, such as torches, typically have a defined range in which they create bright light and a further range of dim light. But beyond this their light still travels a much farther distance. The DMG tells us that:
The light of a torch or lantern helps a character see over a short distance, but other creatures can see that light source from far away. Bright light in an environment of total darkness can be visible for miles, although a clear line of sight over such a distance is rare underground.
From this we understand that obstacles to sunlight, such as clouds or shade cloth or thick and colored glass, reduce the brightness of sunlight without affecting its 'directness'. Even a gloomy day is still bright, but when the sun has been reduced in intensity to a bright moon it is dim. Further reductions might reduce the intensity of the sun to that of a pale moon, and at that point a vampire would no longer be 'in sunlight' despite a visible sun in the sky. Thus the sun could be directly overhead, but if the air was obscured with thick thunderclouds and rain, or sufficient ash, dust, or smoke, then the vampire would not be affected by the wan light that remained because they would categorically be 'in darkness'.
When the OP asks what happens when (4) sunlight comes through clouds or (5) through glass and hits the vampire, the answer is that it depends on how thick the clouds are, or how dark the glass is, and thus how dim the sun has become.
The nature of moonlight and starlight depend on the campaign
OP assumes that moonlight is reflected sunlight and that starlight comes from more distant suns. This may be true within the cosmology of a particular campaign setting, but it is not necessarily so. In 5e, the Spelljammer rules state that (emphases in the original):
Every D&D world - whether round, flat, or some other shape-exists in an airless void known as Wildspace. A world might be solitary, or it might have neighbors: one or more suns, worlds, moons, asteroids, comets, or other bodies. This neighborhood of celestial and planetary bodies is called a Wildspace system.
Thus any given Wildspace system might have one or more worlds, suns, and moons - but such a system does not have stars. And the sun or suns of any given system are not stars to other systems. Rather (emphasis in the original):
If you were to leave your home world and continue outward until you neared the edge your Wildspace system, you would begin to see a faint, silvery haze. By traveling into this haze, you pass from from Wildspace into the Astral Sea, more colorfully known as the Silver Void. The deeper into the Astral Sea you travel, the thicker and brighter the haze becomes, but the stars that shine through it are always visible.
Thus we can see that at least for the default cosmology of 5e, suns and stars are fundamentally different celestial bodies. Suns exist within a specific Wildspace system, while stars are points of light scattered through the Astral1 Sea. From this it follows that 'sunlight' and 'starlight' are different kinds of illumination, and no amount of starlight, no matter how bright, is enough to provoke sunlight hypersensitivity in a vampire, any more than the daylight spell would. Not all campaigns will adopt this cosmology, and it may well be that OP's vampires exist in a world where the stars are, in fact, distant suns. But in this case we fall back to the previous section, noting that no amount of starlight is, RAW, enough to illuminate an area from darkness to dim light, and thus a vampire in starlight is not 'in sunlight' regardless. In neither case then would a vampire be affected when (6) light comes from a distant star and hits them.
Moonlight is a little trickier, because the Spelljammer rules do not explicitly say whether moonlight is reflected sunlight or not2. In at least one official campaign setting prior to 5e, however, it was not. The description given for the Greyhawk setting does not explicitly state that the moonlight from the two moons (Luna and Celene) of the Oerth is not the reflected light of the sun (Liga, or Sol). However, extrapolation from the different stated positions of the sun and moons at different times of the year make it clear that the phases of the moons cannot be explained by the relative positions of the moons and sun, but rather must be a consequence of where the moons are in their orbit around the Oerth, independent of the position of the sun3. Thus, at least within the Greyhawk setting, moonlight is fundamentally different from sunlight.
The answer to OP's final question, what happens when (7) sunlight bounces off the moon and hits the vampire, is thus that in some cosmologies moonlight is not reflected sunlight, but has its own essence, and will not affect vampires. For settings in which the DM has made it clear that moonlight is reflected sunlight, a vampire would be 'in sunlight' on only the brightest of moonlit nights, when the moonlight is sufficient to create the condition of dim lighting. For any moon paler than that, the vampire would be 'in darkness' and unaffected.
1 One notes that the word 'astral' comes from a root which means "star" in Greek.
2 There might be something in the accompanying adventure, but I have not scoured it.
3 In first edition, even this could be explained away by an in-universe narrator who was mistaken in believing a geocentric model for the system. However, once this geocentric model became established as canonical fact in second edition with the publication of Greyspace, it was irrefutable.