If uncle Ben was alive would he want Peter to keep being Spidey?

With great power comes great responsibility, he always said but if he knew about Peter's powers would he support him in being Spider-Man even if it means he's constantly in life-threatening situations?

Yeah. Probably. Most likely.

read more on uncle ben. when he was younger. you will have your answer.

@Kallarkz: I think in the original movie he just meant that Peter should use his strenght responsibly, like not going around beating people up but he wouldn't actually want him to go fight crime.

In this new movie uncle Ben is a bit more of an "act first, think later" type of guy and I think that gets him killed. This version would probably want Peter to be a vigilante superhero.

I'm not sure about how it is in the comics though

he would worry of course but he would encourage him

There was a What If? story that dealt specifically with this, where Ben lived and May died. At the end of it, Ben encouraged him to keep being Spider-Man.