Yes. Not necessarily. Yes.
The DPS it puts out is pretty low, but it can one shot most enemies with a sneak crit, and its sway and spread are so low you can snipe enemies as far as your draw range lets you.
I'm guessing you haven't been fighting enemies with them (NCR), so before you buy, you could try going to Hidden Valley and letting a Paladin snipe you. It's not exactly the same thing (like 2/3 of the base damage I believe), but it'll give you an idea of what a weapon like that could do with upgraded ammo, maximum skills and perks.
Also, one of my favorite weapons in the game is the La Longue Carabine, a fully upgraded Cowboy Repeater with better stats and a scope. You could look into that.