I am going to step into the fray if I may
I think what you also have here is a typical adolescent Labrador, time and time again I here of dogs this age with the same behaviour trait, they sadly end up in rescue for someone else to deal with.. so firstly congratulations for trying with him

The issue here is that as a young pup he was never taught boundaries, unlikely to have been taught bite inhibition and also he is a breed that has boundless energy and needs an outlet and this can come across in negative behaviour.
Firstly, back to basics, whether we want to go with the 'pack' therory or just damn good training theroy, you have to start somewhere.
Sofa, Bed, Chair - these are for humans, so you teach him that, the easiest and most effective way is to take him firmly by gently by his collar and with a FIRM AH or OFF you move him, simple as that, no arguments, no rewards afterwards and no eye contact. Your chair simple.
Biting - this is more than likely a habit that has been formed, he bites he gets YOUR attention, you need to break the cycle, it sounds more like nip and run as opposed to aggressive biting, but I am not there to see it, so taken that its nipping, when he does it, you shout Ouch and walk away, ignore him, Biting is rewarded with no contact.
Jumping up, push firmly down, again, if you make eye contact or speak to him this is to your dog recognising he is there, so for him that action has a reward, again you need to break that cycle.
The thing is, a 7 month old Lab is going to be a force to be reckoned with, and they are highly intelliegent, very manipulative creatures and learn very very quickly what recieves a positive outcome.
They are a gregarious and social breed, so when they do something that is unwantd behaviour ignoring them is the worst punishment.