Yeah his relationship with Micah is like vaguely sizing him up whenever he gets a boost of confidence and then immediately regretting it the moment his dad gives him a mere threatening glance in return. They are pretty distant, and IV doesn't like to see his parents together either, despite the fact he does love them both and there's not really any issues between them (I mean Micah and Jenny at least) at all atp. They're really sweet on and docile with each other here, they're basically only there for each other in this ending. IV just doesn't like it lol.

And ig in the high honor ending, his obsessiveness with trying to scratch up information on his dad isn't sm like admiration of III as his own person (uhh to some extent? he doesn't know anything about III truly / remember him like at all, and the information he gets is never from Jenny, it's from outside sources like old newspaper clippings or word of mouth who were around during his reign of terror, so it's all overly exaggerated and sometimes wrong), but it's more like IV trying to form his own personality based around it, so I'd still call that competitive in a way, even if III is long dead.

He definitely looked up to him when he was in Hagen though, and if they hadn't gone quiet in the neutral ending and instead kept on running and terrorizing the map, IV would have bonded a lot more with Micah and they'd be a lot more relaxed and similar to each other / on the same wavelength, but now they're both like pent up wild animals stuck in a box together that never really got to bond properly.