Yes, you can have an escalating problem on your hands and should consult a trainer.
Just some suggestions:
Do get him neutered!
Try to get him in a basic obedience class. I suggest one with an experienced trainer and not one through one of the pet stores.
Try not to let him have access to those windows.
Do not let him get that close to your face!
Dies he know any basic commands like Sit, Down, Stay?
If he is showing aggression and you can't control him, that may be an accident looking for a place to happen.
There is a lead you can buy at PetsMart (can't remember the name) but it has like a strap that goes around the dog under the front legs. It has a clip to attach a leash in the front. This "may" help with the pulling issues.
Look up NILF (nothing in life is free) training and read up on it and start implementing these methods at home. You have to be consistent and be the pack leader.
Without having a lot of dog experience, I think the best thing you can do is work with a good trainer.
Your Vet may know one or, if you have a local dog club, contact them as they can be a good source for referrals.