Going by parts.
No, there isn't plenty of autowin buttons. Yes a sniper rifle has the abillity to one shot on guy, usually enemies don't wander around alone, so yeah, you take out one of their friends, the others are going to start shooting you then, reason why you normally don't open up with a sniper rifle, normally you open up with some form of CC or mass damage... Before the mk5 grenades was the closest thing you had to an autowin button and even some enemies could take it... Now you don't even have that anymore because it's much harder to craft them.
Limiting materials means that players will be hard pressed to craft anything, in fact this last update made materials available in much larger scale because before they were too hard to find... Well, at least as loot, the merchants is still the same and no, it's not a good thing to limit that kind of stuff because you kinda need it.
Increasing skill to manufacture TNT. You know what is wrong here? The whole problem with the crafting system starts exactly in the point that the required skills are already too high. This means that crafting never keeps you ahead of the curve, it only saves you a bit of money but your stuff is always going to be worst than what you can buy.
Again, it is not that i don't like the idea. I just don't see it as fitting the game lore nor being balanced.