Baby Vegeta vs. Mystic Gohan

I saw him getting his butt pummel in his SSJ form, it does not make sense, when Mystic is available to him, was it the lack of training again?

Lack of training is probably the reason. The same as the Cell/Buu saga gap, a lack of training will keep him around the same level.

However GT's inconstancy kicks in when we have base Gohan not being insta-stomped by Rilldo, who SS1 Goku said was as strong as Buu...

Ignoring that, GT Gohan should be weaker than his Buu saga self and likely unable to achieve that form.

Originally posted by BloodRain
However GT's inconstancy kicks in when we have base Gohan not being insta-stomped by Rilldo, who SS1 Goku said was as strong as Buu...

Stronger, actually

There are a lot of forms for Buu though, so who knows which one he was talking about, though I'd personally lean towards Kid Buu

Anyway, I think even Base Baby Vegeta takes this, considering he smiled off a punch from SSJ3 GT Goku, who is leagues stronger than his Z-Era self

Originally posted by Crimson Dragoon
Stronger, actually

There are a lot of forms for Buu though, so who knows which one he was talking about, though I'd personally lean towards Kid Buu

Anyway, I think even Base Baby Vegeta takes this, considering he smiled off a punch from SSJ3 GT Goku, who is leagues stronger than his Z-Era self

Agreed.