Ah excellent points! I agree wholeheartedly that as it stands now (cap 5 for Abilities) it would be far to easy to unlock the most powerful gear. However, I don't think that the cap is actually 5. It is probably an enforced cap during alpha for a few reasons, first because they want to have things happen as you progress further and those bonuses are simply not done yet. Second because they want to encourage the tester to try out lots of Abilities. Think of it this way; Does it make sense that you can be the best you can be with Fire Magic at Level three? It most certainly does not to me, not when the Abilities simply boost simple values such as damage or allow for more complex spells; there is no reason to have a cap, especially since the Abilities have Diminishing Returns per Ability Point spent. So while I can't refute your argument, I don't think it will come to hold water in the long run.
Personally I don't think gear requirements belong in a game at all. Sure, some basic requirement, so that your character can actually lift the item, sure. Beyond that I say let everyone wield whatever they like. Their skill within each area should decide how well they do with items *of that type* not a specific item. I won't argue that this is good for D:OS though, think it might need the requirement system.
Edit: If I sound angry or confrontational, please take no offense, it is simply my style of arguing and I have no wish to insult or taunt you. I'm happy that you have taken some time to answer me
