Not sure that Katter is one of those who would be prepared to man the barricades to the bitter end on the issue. Homophobic, certainly, but more to the point: I think he simply does not give a shit about such issues. Industry, agriculture and big infrastructure (specifically in the north): those are his hobby horses.
I think it depends how much homophobia becomes a vote-winning rallying cry for Katter's new party. If the party just becomes a predictable one-man-in-one-electorate sort of affair, then I don't doubt you're dead right, but if it somehow gets traction ... well, I was initially thinking no way in hell it would, but Queensland's pretty much just been waiting for One Nation v2.0.
It's no secret he served as a minister under Joh: much as I loathe that era, I'm not sure this in itself is evidence of corruption. Mike Ahern, Joh's ultimate successor, was likewise a long serving minister. As was Bill Gunn, the deputy premier who started the clock on the downfall of the whole house of cards.
Oh yeah, I'm not suggesting it is evidence of corruption, just that I'm surprised more hasn't been made of it (I suppose because the media sorts who love to dredge up unfortunate aspects of the past are in this case generally sympathetic to Katter to some degree). I mean, when I lived in Queensland, it seemed any mention of association with Joh was uttered in the same way you would tell somebody "yeah, he murdered his mother".