Welcome to PetTalk! (By the way, don't apologize for your English--it's much better than that of many Americans!)

I have a few suggestions, since Eli too was a young male dog not long ago:

* Clean up all accidents with an enzymatic cleaner like Nature's Miracle (or similar brands found at pet stores)--only this kind of cleaner will get the scent out of the fabric so that the dog doesn't go back and mark the spot again!
* It's very common for housebroken dogs to regress at some point, and at 4 months the "teenage" time could be starting. Don't be surprised if he's a handful for the next few months.
* With a new puppy, you might want to make sure that he definitely acknowledges YOU as his superior and leader, which means don't let him up on the furniture with you. Keep him below you, on the floor.
* He also might be acting out and growling because of the attention you're giving your boyfriend. Eli did this in his teenage months, and sometimes still does: he'll get obnoxious and start barking or bringing toys to me if I move over and share the couch with my husband. Again, keeping the puppy down off the couch at these times could help.
* And finally, if this is a dominance problem you might seriously consider getting him neutered soon. It probably won't make a huge difference, but it should help with the humping at the very least!

When you move to the new place, make it a happy fun day for him as much as you can (keep him out of the hectic part), find a place for his dishes and bed as soon as possible and don't change those places, and watch him like a hawk for the first few weeks--don't let him have ANY accidents in the new home!

Good luck!