If we don't know how powerful the Norse heroes are, how can you come to the conclusion that he isn't fully powered? Like Gaius said, his flying in that issue had more to do with him being a spirit/ghost, but even if it didn't him flying doesn't mean he was ever as powerful as Wonder Woman in life to begin with. His memories being intact and hers not leading to her powers fluctuating (but coming back the more remembers) doesn't contradict anything. It's pretty straight forward.
There really isn't any reason to bring him in as an example though. We can infer that he'd deal with the same situation, but it's not his book or creative team, nor are Gods his typical wheelhouse anyway. So it's moot
I don't care for decompression either, but that's an industry wide problem, and this isn't even that bad compared to others.
Overall reception of the run is very positive so far. Doubtless there are people who aren't wild about it (there always are for everything), but most fans don't seem too bothered by these elements. Or at least are satisfied enough with other aspects (use of old villains, exploring the Multiverse, Diana's voice) that they can overlook it.