What you have described, almost exactly, other than excessive play with our other dogs never escalated, and she would almost obsessively jump up at people, is Connie, the pup we bred and took back at six months old.
In her case, it wasn't that she wasn't trained, more that the previous owners had inadvertantly trained her to do all the ridiculous things she did (like jumpiing up) and to ignore all of their commands. She will be two in October, and although she is a completely different dog to when we got her, she still has her 'moments'. She will occasionally still try to pull on the lead when she gets excited, and will sometimes decide she isn't going to come in from the garden unless what you offer her is really worth it. (so, she won't recall from the gardenfor a bit of kibble, but probably will for a bit of cheese. (she's got me better trained that I think.... however, I suspect she'd actually live in the garden given the chance, and I was also trying to train her not to dig out there, so couldn't leave her out unsupervised...
I would suggest maybe looking for a trainer/behaviourist on www.apdt.co.uk
. Quite a few on there also offer socialisaton classes and I have known of several that offer 'dog walking meets' whee everyone from class meets up socially for walks.
I'd also suggest buying a copy of 'The Culture Clash' by Jean Donaldson. it's not a training book, an dit's not really a dog psychology book, but it does help owners to understand why their dogs behave the way they do, and what motivates them. I personally think it should be an absolute must for new dog owners.