Limited Powerful Feats (3.5e Variant Rule)

Limited Powerful Feats
The SRD comes with almost no really powerful feats: Natural Spell and maybe Leadership. Even with all WotC sourcebooks allowed, it is quite difficult to find a character with only Very High balance feats, or even more than one or two. With dnd-wiki, however, Very High balance feats with easy prerequisites are a dime a dozen, making it easy to get too much of a good thing.

Solution
Each character is limited to 1 Very High balance feat. That maximum increases by 1 for every 8 levels in Very High balance classes, 4 levels in High balance classes, 2 levels in Moderate or Low balance classes, or some combination thereof (i.e., a Soulsmith 3, Fighter 1, Tome Barbarian 6 could have a maximum of 3 Very High balance feats).

Other Balance Points
Shift balance level down appropriately; it's unlikely that a Moderate balance game would work well with any Very High balance feats. TWFer Rogues, after all, are normally High balance with just the Fighter-level TWF.

Not All Very High Balance Feats Are Such For The Same Reason
Some Very High balance feats are not listed as such because they typically cause a major boost in power for a Very High balance character; some are that way just because they do things only Very High balance characters are allowed to do, like hand out mass SoDs. Such feats could reasonably be exempted from this maximum limit, but identifying which ones they are is probably too much work.