Same here. I rarely develop the gun skill(s) much.
Likewise, although I usually end up with a couple of them really high by the end anyway.
As mentioned in another thread, I have developed a build wherein all 5 combat skill are raised more or less evenly, the idea being a character who uses whatever he or she finds rather than sticking with a particular set of weapons.
As to the OP's question: I do, in fact, have a character with 100 in both Guns and EW, although I found myself wishing one of the two had been Explosives since neither Guns nor EW offers much in the way of AoE damage.
I have deliberately
not been putting a lot of points into Sneak; just enough to push it to 50 with all the skill books, so I can take Silent Running on those characters that I feel should be a bit better at sneaking around. No more invisible snipers for me.