You are right to be concerned - what appears to be puppy high spirits can quickly become very unfunny as the dog matures. I always feel the best way to deal with this kind of behaviour is exactly the same way as the rest of a pack of wild canids would deal with it. To forge the strong bonds needed a pup needs to learn the social rules and language of the pack. When a young pup steps over the comfort mark when playing with an adult the adult simply gets up and walks away ignoring all atempts by the pup to re-engage it. The pup quickly learns the accepted way to play and as the pup wants social interaction and play to continue will modify its behaviour in order to prolong periods of play. Play with other pups also teaches self control in a similar way. If a pup bites a play mate too hard or becomes too boistrous the puppy on the receiving end squeals loudly and moves away from the offending puppy, thus stopping the play and interaction that the first puppy wants. In order to keep playmates interested in playing with him the pup must learn to control his play behaviour and his bite. These are vital lessons for any pup to learn when young, if he fails to learn them his future is bleak - other pack members will become less tolerant of his behaviour as he matures and will physically admonish him, eventually causing injury and almost certainly excluding him from the pack altogether. His status within the pack will always be low and he faces an early demise on his own.
When pups are brought up in a human pack it is just as important for them to learn the boundaries of acceptable behaviour - many millions have been abandonded or euthanised because these important stages of development have been missed. Many more owners, especially those with smaller breeds, live an uncomfortable life with an unpredictable animal that they fear.
Your friend and yourself should agree the limits that are acceptable (for myself, biting is unnaceptable as is jumping up, especially when directed at the face) and each and every time, without fail, the limits are broken you get up and walk away from the pup. Use a clock and time at least three minutes AFTER the pup has stopped trying to gain your attention before calling him back to you and praising him calmly for good behaviour. I would not engage in ANY tug of war game with him - you could concentrate on fetching games instead which will also help with recall and "give". Using treats to encourage the pup to give up his toy is a great way to start, if he still refuses to relinquish the toy then get up and walk away, timing as above. If biting occurs squeal really loud as though he has hurt you, get up and walk away - following the timing rule above. It is important to time only after the pup has stopped trying to gain your attention and also to totally ignore the pup until the three minutes are up - ignoring includes no speaking to, looking at or touching the pup. This is easiest done while standing up - go into the kitchen and have a book or magazine ready on the work top to read so that you can keep your back to the pup. This is hard work at first and takes practice but I PROMISE it will work as long as you are rigid in sticking to it - you will be, after all, talking the same language as the dog! Try and find puppy playmates as well as older dogs to help the socialisation.
Good luck