People usually use auxiliary verbs when they talk. I have watched Friends before and have heard do and did in there. It can be hard to pick up on though. Here are examples of did and do used in speaking: I did this already, I did think they were cute, I do believe that happened.

You have to remember that this is a colloquial style and, if you're ever in doubt, you must stay with the standard forms of English. There's nothing wrong with them. To answer your question, yes auxiliary verbs might be dropped in a question in *very* casual speech. (Did) You see her? (Have) You seen her? (Are) You seeing her? It's much harder to drop modal verbs and maintain the same meaning. If anyone came up to me and started asking questions AND dropping the auxiliary verbs, I'd think they were a bit rude and stupid. My point is, remember exactly who you're talking to. Do you know them well enough? You won't do yourself any favours if you decide to speak your second language in a sloppy way.