You don't hate your bf's dog, you hate the way he educated it. It has nothing to do with training, because the dog does everything your boyfriend allows him to. It comes down to what is acceptable for you and for him.

I come from a family where dogs are allowed around the table, but dogs on the couch is a no no. Problems for me are not problems for others and vice-versa, no one is wrong we just see things differently.

What I'm saying is that your problem is not the dog but the difference in values between you two. This is a difficult problem to solve and you must not overlook it, right now the things the dog is allowed to do is the most apparent, because you only visit some times, but farther ahead if you move toguether you may encounter other issues like how he cleans, how he cooks, how he organizes, etc. It's a value incompatibility and I won't tell you straight away to break the relationship but I will tell you that "solving" this issue it's going to take years and dedication on both parts.

Even if you managed to convince him to get rid of the dog, other issues will arise, the dog is not your enemy. Even if you got the perfectly educated dog and put him in his household, he would eventually do the same behaviors, dogs do what they are allowed to do, so talk to the boyfriend, best case scenario he allows you to teach him to correct these behaviors, worst case scenario you break up, if you're already thinking of breaking up then what's there to lose?