That absolutely sounds like Henry at that age. He started mouthing again for attention and nipping my ankles if I wasn't paying him attention. And it was at this age that he started barking at things that hadn't bothered him before.
It does pass, but it's worth nipping in the bud behaviours you don't want. If Henry was being attention seeking in an annoying way, I'd ignore him, and then try to remember to give him positive reinforcement for the behaviour I did want. So if he asked nicely to play, I'd play, if he barked or nipped I'd ignore him. If he asked nicely at a moment where I couldn't play, and then went to lie down instead of barking at me, I'd drop a treat at his paws where he was lying. The sort of thing. Catching and reinforcing the good behaviours now is a great way of laying down the foundations for a 'good' dog when this phase passes!
We also made sure we dealt with barking as soon as it started at this age - we'd try to catch him after one or two barks with a click and treat for stopping and paying attention to us. Doing this consistently means he mostly only barks once at things like the postman, people passing, etc. There are other things where we can't stop him barking like a lunatic - such as when the cheeky young foxes parade around in his garden! - but we don't have a problem with him generally barking at everything, and I think that's because we intervened positively early on.
It's very trying age, but it does pass!
