その言葉は殆どだめですから、使えば気をつけてくださいね！

On Ice- 色んな意味がありますね。たいてい「何かを延期する」の意味があると思いますね。殺すの意味もあると思いますが、違うかもしれません。アイスはクリスタル・メスの意味もありますが、この場合には違うと思います。例の分がありますか。

It can have different meanings, kind of depends on the context. A lot of the time it can mean to delay or postpone something (to put the plan on ice), though it can also mean to kill someone (Ice them). Ice can also be slang for crystal meth, though I don't think it applies in this situation.

「punk ass motherfucka」はすごくだめな言葉ですよ。普通に意味は殆どないでしょうが、侮辱として使います。

This is a really bad phrase. It generally doesn't have a whole lot of meaning behind it, but it's mostly used as an insult. It can kind of imply someone who for whatever reason rose to their current status or achieved something without having to do much work themselves, but I don't think that much thought usually goes into it.

Wanksta

暴力団として勤めるのに、実は暴力団のことをしないので、本当の暴力団じゃない人です。

Someone who acts like a gangster, but isn't really one, as they don't actually do any gangster things.

Damn
クソと大体同じです。
It's about the same as "クソ".

I'ma

ちょっと分かりませんね。 「I'm a」 でしょうか。

I kind of don't understand what this is. Maybe it's "I'm a"? Like "I am a"?

Thank you for answear my questions!