So what skills do you think, that should be raised and to what level? I think Survival or Medicine and Science or Lock Picking and Sneaking.

Nothing really, so long as you have a decent set of skills. Sneak is probably the strongest after Speech, though. If you're a social based character, the companions are usually competent enough to handle the fighting when you must fight.

Survival's been weak for me. Medicine too. Science I haven't seen any need beyond 25, same goes for Lock Pick. Sneaking's been a choice for only when I wanted to avoid combat, never necessary when I want to shoot my way through.

They've been pretty good about nothing being must haves.

There are things that require a higher science or lock picking to get loot.

There aren't any skills that any class needs. It depends on your build and the perks you want to pick as several of them have skill requirements.

I'd say that most can get by on Medicine, Speech and one weapon style. If it's a firearm style, add Science (or Energy Weapons) or repair (for Guns) for ammunition purposes. I'd say that's more or less all you need for the most basic of basic needs in the game, and it's possible to drop speech if you'd just rather blast anyone who doesn't listen to you.

I had meant to say, skills that would be useful for any build.