Potential Skills Bonuses

Just two questions about this.
lvl
1 - Is it possible to get these skills from any item (I know it' just hat, shoes, gloves and maybe pants?) lvl 100 or above, or just any equipment?

2 - is it intended that once you get an item and the skill, you can switch to another equipment and even sell it, and still keep the skill? Because that's how it is working right now.

If the second one is not intended, what are the chances of one getting ...screwed over by nexon (banned?) for getting these skills and selling the equipment?

Thank you.

1 - hb (pants), haste (shoes), door (hat) are on level 70+ items. SE (gloves) is on level 120+ items.
2 - who knows if it's intended. That's how it works everywhere these skills are available.

So it works like that in other versions of MS?