That's mating behavior. With two male drakes, they will often take out their sexual urges on each other because they have no other outlet. I used to keep just two male ducks as pets and they would chase each other around and pin each other, but it never led to injury so I wasn't worried about it. Your pekin though is much bigger than your swedish so he could easily injure him doing this.
I really wouldn't keep them together for much longer if this continues or gets more aggressive since the swedish could get seriously hurt from this at any time. You can try splitting them up but then they will both just be miserable and lonely. You could try getting them some girls to keep them happy, or you could rehome the pekin drake and get a female for your swedish, or the other way around (actually preferably three or four girls if you can swing it).
As for the food thing, that's just normal pecking order stuff. Try putting out a couple more feeders so the male pekin can't guard them all. That at least will help with that until you can figure out what you're going to do.
