In order to successfully use many parallell processes in conjuction with one another, you're going to have to introduce conditional branches in their use, so that, though they're constantly checking, most of the time this is process is simply "is this true? No...okay" or "Oh look I need to add +1 to a variable, cool, thats all".
Ideally, if you can, add some variables in there.
So your event should run:
-Have a conditional of Is Variable(x) != Variable
? Uncheck the box for 'if conditions don't apply' on this one.
--Now check your equipment with Is Character[Bob]= [Sexy Ring] Equipped?
---If yes, Does Bob have Skill [Sexy Ring Fireball]?
----If yes, Do Nothing
----If no, Add [Sexy Ring Fireball]
---If no, Does Bob have Skill [Sexy Ring Fireball]?
----If yes, Remove [Sexy Ring Fireball]
----If no, Do Nothing
--Irregardless of what happens above, Now put Control Variables Set
= (x)
-Finally, outside of the conditional, Set (x) to Player[Bob] Strength or something
Therefore, whenever this goes off, if Variables x and y are the same, it ignores everything except the final part, which sets x to Bobs Strength. So if Bob's Strength changes, it is no longer equal to the stored value of [y] and the skill alteration triggers. Change the reference to Strength to something that equipping the item changes (it might be INT, or something). This is the easiest way of only running the event when that persons equipment changed. It does assume that equipping something is going to alter a stat.
Alternatively, a more foolproof way would require that you delve into the Script for the equipment screen, force it change a switch everytime you're there, and control the common event that way. But thats a bit more intermediate.
