I'm trying to build my character sniper-stealthy.
Well, you may want to think about this for a second. What's so stealthy, exactly, about an extremely bright line (laser) or a giant glowing ball (plasma) that directly points to your location
Are Energy Weapons more common than on FO3, and therefore more viable as a main weapon to play the game from start to end?
They're about the same. In Freeside, (a town that's right next to New Vegas) there's a store that sells only energy weapons, they have a pretty huge stock and you really can find all types. The only problem is that their store is
1: Heavily guarded on the inside
2: Most of their actual stock is layed out on a table and can ONLY be stolen.
Energy Weapons are not a very viable weapon. From the start of the game until New Vegas, I never saw an energy weapon until I reached the city. Also, your starting guns are also some of the best guns in the game if I don't mind saying. For example, I still use the Hipower (or 9mm pistol)
I only noticed that there are no Sniper Energy Weapons, so are EW just close-combat weapons, like pray-and-spray?
I'm pretty sure the Gauss Rifle has a scope, and the laser rifle is pretty accurate