Can I keep it, I have 5xp leftover and I want to save it.

Yes.

Also yes.

A few of my players have done this in different games. If there is a talent or third level of a skill you want to be able to purchase sooner rather than later, it can be worthwhile to leave that XP hanging rather than just purchasing rank 1 in another career skill or a tier 1 talent.

You can keep it but id highly suggest investing in your base stats as much as possible, you can get talents, force powers and skills anytime but increasing your stats costs a hell of alot more later

I have but 5xp doesn't buy much besides skills or talents

Got access to Cool or Vigilance as career skills? If so and you don't have ranks that's a good spot.

It's safe to save xp, but some talent trees has some pretty good talents at the 5 xp level so check everything beforehand

Oh, dear me, YES!

Saving Exp for future bigger purchases is always acceptable in every RPG. And for some of the more expensive talents, its necessary later on as you continue to play in a lengthy campaign.

I'd also like to echo 2P51's advice. Cool and Vigilance are very important skills for this game.

I save at least 15 xp to boost my character's chosen stat up to rank 3. During character creation, I'd follow the 2-rank-max limit, and immediately after the game begins…hello rank three! That's one of the reasons that I mostly GM now, I was not a very popular player.