First off, Tucker's eyes, unlike all the other characters. are looking directly at the player and ignoring Danny when he's talking to him. (It really creeps me out.)
Yeah, we just don't have everybody's eyes and expressions done, and Tucker was just drawn with eyes facing out, as per what Psymind felt like doing with it. Will be fixed in due time, hopefully when Psy can go full-time.
You might explain during the into or elsewhere that the last season of the show haven't happened. Danny being exposed to everybody as Ghost Boy when he and all the other ghosts save the world from the asteroid and he falls for Sam.
I get this sentiment, but also don't rightly have any good idea at the moment as to how to do so without it being 4th wall breaking. Even through an omnipotent narrator like Clockwork or the Watchers, they'd have to express words like "skipped the third season" without it sounding goofy... I'll try and make it clear that this dimension is different from even the main show dimension, but I feel we haven't gotten to that point yet where that'd be necessary.
Everything else is valid and will try to take time to adjust.