Alright, you need to understand something here.
Time is relative.
Just like if you asked me if I was holding something big. Big compared to what? It's just an opinion without something to compare it to. An ant is freakin HUGE if you're an electron.
Similarly, time passes differently depending on, among other things, your speed of travel. But it's not the way you think. When you're stuck in traffic, time is actually going by faster than when you're cruising at 60 MPH. Time slows the faster you go, that's called time dialation. But you're not aware of this. Even the clock on your dashboard isn't. It'll keep ticking the moments away just the same even if you're going lightspeed.
The rest of the universe won't. You're traveling at lightspeed past a planet and you see a generation live and die within a second.
But they aren't aware of this either. Time is ticking by on their clocks, just the same as it's ticking away on yours, and when you get back to earth, you're left to figure out who's clock is wrong.
As for your other question, I don't even know how to qualifty that, so I'm just gonna say 'Sure, why not?'