Roos do what they were designed to do, put boy stuff where it can get to the eggs.
It may look pretty crazy to our eyes, but its successful to chickens for a long time. As long as the girls backs are fully feathered and he doesnt peck them there's nothing to worry about. If he is mean and doesnt do his dance before he jumps on then maybe its time for a new rooster. I'm always one to give a chance to a roo if they dont understand people are freinds, but if hes mean to the girls that's making him pointless.
Other than babies a roosters job is to be nice, find food, and protect the flock from danger, not be dangerous.
To get back to the question yes a rooster can get lonely, however all they do is crow A Lot more and it wont hurt them long term.
Do be prepared for some aggressive mating when he is put back in as he will have a lot of hormones running through him just like any man who has been cooped up alone a long time. As they age they get a better handle on the hormone surges, but a youg guy is in a tough spot understaning what he should do and what he wants to do.
