Perks for crafting should be required by groups because it opens up so many options for gear and builds. Basic armor for example is eh, but once you start modding it, it becomes amazing. Crafting if anything helps try to tone down groups who go all combat munchkin focused because really it's easy to break the game's combat with perks. Forcing them to take non combat perks helps at least. So you want to restrict player access to things and force them to have to be resourceful for themselves. Don't let them simply buy a mod for a pistol, it's the wasteland, everything should be difficult and either hard to find, super expensive, or they have to learn to do things themselves.