The shifty skin hat, even though it is level 8, could be equiped at lvl 7. I didn't try at other level, but when you take the item from ther store and put it directly on your equipement slot, it can be equiped.
There are no level restrictions on items. There is, instead, a sort of "malleable level restriction" system based on these things called "talents" http://www.cardhunter.com/2012/03/borgo-the-talented As you go up in level, you will get "talents" that you can use to equip more powerful items. Until you see talent restrictions, there is nothing to stop you from equipping any item in the appropriate slot.
