Well, for the skirt, I haven't anyone either (it the slot for the swimsuit bottom so mauybe it's mean to be empty...).
The log & butterfly are a pain since they are always outside of the map path, you have to explore every nook and bush of every map....
From memory, I think the last roudn blue crystal boost the magic cannon (aka rocket launcher max ammo and damage. Which is basically only really useful by then to do the archievement for the last couple of stage doing S rank since it's faster to kill the bosses).
Translating all the archivement with tool will be way too long, so I can upload my save with all archivements finished (not all map & difficulty on S rank though, lost the motivation to do it once I had everything as far as could tell).