As you stated, Raul offers repair services, however you still have to pay him and I am not sure if you get much, if any, of a discount. Also, he can't be your follower if you want him to repair things. You have to dismiss him back to his shack, not the Lucky 38. So, if you want to repair things cheap and whereever you are, you still need Repair Skills or Repair Kits. He does slow down how fast you damage your weapons from use, and if you mix in Bulk Ammo, you may rarely ever have to repair anything.
As for combat, he is a pistol shooter, not sure if he likes rifles or not. He is not much on Melee, but that could just be from the battles I have had did not need it. However Raul seems to go for the Melee less often than say Boone does.
TBH, I don't tailor my character for my Followers, I make my character do what I need them to do for the Role I am playing, and then have the follower along to be a bullet sponge or comic relief or to be back up in a fight. Sometimes I just let my follower take care of things as I go along. I have not seen a follower that is so well versed in anyone thing that I could have my PC gimped in that skill. Although Veronica with her devestating Unarmed attacks do offer a tactical balance to my prefered ranged weapon attacks. So, if I have her along, I ignore Unarmed for my PC.