The Eberron/UA Action Point system is FAR too generous with AP per level. Far, far too generous. I found there were two serious negative effects on my game from the Eberron AP system:
1. Saves against nasty status effects become meaningless, because PCs always spend an AP to avoid the efffect. This renders the monsters' flavor and special attacks moot, making combats all feel same-same because monsters capstone abilities never actually function against PCs.
2. This is the really big one -- Time per PC turn at the table during combat increases dramatically, because there is a constant meta-calculation occurring in the players' minds each time they roll d20.... "Did I roll high enough that an AP will make a difference in success/failure?" Ok, spend the AP. Now, roll the d6 or multi-d6... now take the highest and add it to the d20 roll... ok, did I succeed?
I backed away from the as-written AP system after I found my players abusing it, and went with a no-AP campaign. I was startled by how much faster combats ran (and I tend to run fast combats anyway, in any edition) when the AP were removed.
Were you to try the Hero Points from APG, stick with 3 per level and try the RAW first before houserules, is my suggestion. More than 3 Hero Points or AP-style points per level is just asking for metagaming, slow play, and hoarding/abuse.