well I'm not going to bother quoting you're whole message Bill, so I'm just going to respond.
Alright, I'll grant you the point about the germans catching up to goddard, but again, the real difference maker for them was still government funding. Even with the additional skilled personell, without government backing the germans arent going to be getting into space very quickly or at all, same thing goes for Goddard. Besides the OP was asking for the earliest possible manned spaceflight, and since Goddard was the most advanced early on he is your most likely candidate to get your earliest possible manned space flight, not the Germans, this is of course ignoring the other stipulation that the country involved be either the US or USSR. You mentioned big expensive projects like the Graf Zepplin and Hindenburg, as well as butterflying away WWII. The problem is, without the Nazi party in power in germany the weimar republic is not very likely to fund big expensive projects like a rocket program or massive zepplins, and since having the nazi's almost guarantees the start of WWII, then you most likely wouldn't have a government funded rocket project if there was no WWII. And of course resources thrown at rocketry can't be thrown at something like tanks or bombers or the navy, so you get a less successful wermacht and a quicker defeat for the Germans in WWII and thus an abrupt end to a german rocket program. Also I'm not entirely sure that Germany under the Kaiser would be willing to fund something as oddball as rockets, but that could be debated.
Now it's always possible that you could have a POD where a guy is born or doesn't die who invents like 6 things 30 years early which allows for spaceflight way ahead of schedule in china or turkey or something, but I tend to think that most people would consider that to be ASB. The problem with throwing out really early POD's is that the further you get from it, the more the TL is based upon conjecture and guesswork than actual facts. So a POD in 1901 leaves too much to chance to avoid delving into making things up as you go along. As such Goddard is your most likely source of early space flight without delving into massive amounts of conjecture and creative fiction. This is why I think works like Peshawar Lancers and the Draka TL are more or less pure fiction, albiet with some elements of alternate history but really there is very little historical basis for those works.