Priority is bottom first, top last?

Also say for instance you make a new rule type "show", under that rule type, if you only tick the box for "magic" and no other boxes, it shows/hides all magic items by default? But if you specify anything else (say helms) it'll only show magic helms and nothing else, overriding the default condition?

It executes top to bottom. Put a rule on top that hide everything then make rule 2 and so on, showing specific stuffs. I ll know the logic

Order is irrelevant.
Show has higher priority than Hide.

That's it