Dallas, that is way to much to be burning. I would take it to a Merc auth mech. I've heard of a 500hp burning a qt a trip. He took it in and they ended up replacing the motor. Rings never seated right. This why Merc came out with a service letter telling people how to break it in, along with the 496 HO and Mag. I would get it in asap and get it looked at. That oil use alone will kill your pocket book. This not at all normal. The place that told you to keep a eye on it, don't take it there. Thank god you have a warranty. Here is Merc's number 405-743-6566. Tell them what is going on and they will send you in the right direction
BF......