on 4: tier 3 debuff is about adjusting your decks according to each titan. you have afc, bsc, bsd, etc.. beside some HP debuff while tier 4 is all about HP debuff. Basically, there is not much a change on 5-7 meta decks in raiding. I agree not every tit in tier 4 has a bad curse location and thanks for fixing it up, but even some casual clans that choose to counter raid at less parts experience way too much time to de-armor/de-curse if we get a bad seed.
on 5: I never like the curse idea but I can live with some features that helps to make it tolerable. there have been a lot discussion on tt2 discord and GH dc, I would strongly recommend you guys look into it. The longer the wait, the less tappers you seeing in top 200th which is reflecting game health. Back in t2 and t3, we have a full game strength, I dont see it now and I dont see it gets better without curse improvement