Viking Bastard
Adventurer
without skills it will take away from skill challenges and other "chances" to RP, and DnD is the first RPG ever. We need skills for sure. As for feats i think we need them too. Me and my friends (from time to time) play a RPG called Rifts. Rifts has no feats in it and it really hurts character customization. I think they should be core.
Skills, feats, and themes should be core.
3e was the first edition to have skills in the core of the game. A lot of people think that skills were detrimental to the RP parts of the game, not vice versa (I'm not making that point myself, but it's not an uncommon claim).