Answered that mostly in my notp tag, in which annabellioncourt answered the aged-up Claudia question very well:

I’ve thought a lot on the Claudia/Louis thing, and while I don’t think an aged up Claudia would give a second thought to ravishing Louis, she’s a symbol for everything that horrifies him about himself, and I don’t think that that would exactly be grounds for amorous thoughts. Sure, he loves her and cares for her, but I think if she was an adult, it’d be a lot easier for him to see just how far mentally out there she is, how evil, how unable to understand human goodness she had grown to be.

With Lestat, I think it would be much the same.

I think Claudia still would have tried to kill Lestat, bc she was after his power, too, and disgruntled that he wouldn’t give them the answers about their origins as a species.

Armand still would have had his coven kill her (one could argue whether he orchestrated that or just went along with Santiago’s decision) because he wanted Louis all to himself, and knew that Louis would have a hard time ever separating himself from Claudia.