I had a big ol' write up with answers to everything, then accidentally ctrl+A backspaced it SO OH WELL, it's probably for the best.
But here are some things that weren't mentioned yet that I wanted to say.
- Make sure you are certain of both of their sexes! One, you really don't want one of them to become pregnant, and two it might explain their fighting a bit more. Two males typically cannot get along in anything smaller than a 2x5 or sometimes a 2x4 c and c, and even two females will tussle in close quarters. Once you get the c and c set up though, they should hopefully get along.
- As said, make sure they get 1 cup of veggies each daily--some good and easily prepared choices could be a leaf of lettuce each (red, green, butterhead, romaine), 1/8 a bell pepper, 1 baby carrot, and maybe one other daily veggie per pig. So for the both of them, just double the amounts. Two leaves, 1/4 pepper, 2 carrots. You don't have to be a Top Chef to make a nice veggie meal like this, and this way you can de-seed and cut the peppers into sections on the weekend and every day when they get their veggies you can put their pepper slices and carrots on top of the lettuce like a little plate and let them chow down. That's what I do, and it works rather nicely.

I give 2 cherry tomatoes instead of carrots, though, and raddichio as a fourth veggie. It's really expensive for one raddichio though, jeez...like $2.50 for one little one. But he loves it, so that's good. I would give a carrot, too, but he hates them and throws them out of the cage.
- As for them peeing and pooping in the bowl, I have two theories. One, it's so big they do just sit in it and go to the bathroom. In which case you can get a smaller bowl or two, and hopefully that'll keep them from using it as a toilet. Or they could just be kicking poop in there, which is very likely. However there is not solution to that--they're guinea pigs after all, so just pick the poops out if you see them.
- And it's okay if they don't chew on the applewood. Most pigs won't bother with gnawing, but some do. It's okay if they don't, though, so long as they have good hay eating that will grind down their teeth. Speaking of, it's alright if they kick hay around. Mine loves to burrow in his, so I let him. The only downside is it should be changed out almost daily, as they often pee in it and that can make it mold and soils it. That's one of the reasons people use hay racks--but I love the Mountain Dew hay box, that's fantastic.
- And once they're moved into their bigger cage and have had some time to adjust, they'll come to recognize you as something that is nice and gives them Good Times and Veggies, and they hopefully won't be as skiddish. For now, it's okay if they're a bit spooked, that's very normal. But I know with the power of patience, love, and vegetables they'll warm up to you.
So with that, I hope you have found the answers you seek, and if you have any more questions, feel free to ask! Just make sure you post some sweet pictures of them and their new cage when you get it set up, I know they'll love it.