これもしかしたら最後のスタック・エクスチェンジの投稿になるかもなのです。
その質問はちょっとムズイかもだから、パスします。
Everywhere I looked「かも」is listed as 助詞. Does this mean some particles behave like nouns? It's also interesting to note that 「かも」comes from「かもしれない」which conjugates like an i-adjective. Off the top of my head I haven't thought of any other similar contractions/particles, but I think there should be more examples.
Come to think of it, 「からの」, 「での」...
だ can follow something other than a noun/na-adjective in standard Japanese:
That said, your examples are not very "standard". かもなのです smells to me like a role language or キャラ語尾 known as なのだ口調/なのです口調. As a キャラ語尾 in anime/manga, even something like 見ましょうなのです, 見ろです, 見てくださいなのです or 見ろなのだ is not rare. Although a native speaker in the real world may occasionally say ～かもなのです colloquially or half-jokingly, this should be used sparingly and only in very informal settings. ～かもだ/～かもです is relatively more tolerated as 若者言葉 (e.g., (そう)かもですけど = (そう)かもだけど = "that may be true but"), but you have to avoid it in formal sentences.
