I've heard the crown affects some armor perks and it can be improved like armor can (but has no armor value).

My question is does it count as light armor for the perks? Such as windwalker, custom fit etc.

no it counts as clothing

Are you guessing?

Quite a few items don't have the correct armor type. Diadem of the savant, tulius' armor, fine armguards etc.

Could someone test this please?