Questions about Japanese grammar: colloquial questions, particles, etc. ^.^?

Colloquial expressions are tricky b/c they vary depending on your gender or your dialects etc. Born in Tokyo and female, I would say:

1.
Nan desu ka? -> Nani?
Doko he ikimasu ka? -> Doko iku no（どこ行くの）?
Nani wo shimasu ka? -> Nani suru(何する)? or Nani su-n no(何すんの)? ( "ru" in "suru" disappears and changes to "su-n")
Suki desu ka? -> Kore Suki? （これ好き？） (Adding noun sounds natural to me) or Kore suki kana?(これ好きかな？）

2. It means "What are you doing?"
I would say "Nani shite-n no（何してんの）?" (again "ru" disappears) , "Nani shiteru no?(何してるの)" or "Nani yatten-no?(何やってんの)"

3.
This one varies a lot depending on your gender.

As a female, I would say "Ano hito ga suki nan dayone" or "Ano hito no koto ga suki." If I want to convey that I just fell in love with "ano hito," I would say "Ano hito no koto ga suki ni na-tcha-tta (あの人のことが好きになっちゃった)," which I feel that I've heard often in conversations or TV dramas. Since we tend to prefer vague expressions especially for this kind of emotions, we often add "mitai (means "it seems")" like "Ano hito no koto ga suki ni na-tcha-tta mitai (あの人のことが好きになっちゃったみたい)."

If it's male, I would imagine that they would say like "aitsu no koto ga suki nan da yo ne." But it sounds female to people in other areas, in Osaka in particular.

Also note that those expressions vary depending on the context.

This is a kind of dialect, especially in the Kansai district. "作るんや" is "作るのです" (affirmation) or "作るのですか" (question, with a rising intonation).

1. Nan desu ka? - Nani ka?
Doko e ikimasu ka? - Doko e iku no ka?
Nani o shimasu ka? - Nani o suru no ka?
Suki desu ka? - Suki ka?

2. What are you doing?

3. Watakushi wa, ano hito ga suki desu.

You meant friendly form?

- 何ですか？ --- 何？(What?) or 何かな？
- どこへ行きますか？ --- どこ行くの？
- 何をしますか？ --- 何するの？(What will you do?) 何する？(What shall we do?)
- 好きですか？ --- 好きなの？

何をしてるの？ --- What are you doing?

私はあの人が好きだ。
But I would say like this.
私、あの人のことが好き。