As Amercha says it really doesn't matter much. The only thing that BAB can exclusively help you with is qualification of certain feats/PrC's earlier and the full amount you can Power Attack. In general yes it makes it easier to hit things but BAB hardly is the only way. A lawful Incarnate truly shown how absolutely insignificant BAB can be as when you take into consideration its aura and soulmelds(Avatar, weapon..etc) it had a better attack bonus than a lot of the dedicated fighting classes. Yes, I also know that BAB provides iteratives but the Incarnate's crazy, feral cousin proves that benefit is small as well. The Blade Scholar makes up the difference+ to your class with one feat(Knowledge Devotion) with its fantastic skills. Early on in 3.X the developers overvalued base attack bonus so don't worry about it for making the same mistake.
What you need is a unique mechanic that is imbedded in a theme you want to create. It is easy to say I want a character that can learn anything in a given area. So, what do you specifically want here? A skirmishing wanderer? A tactical warrior? Please point us in a direction so we can help you fill it in.
A class that can learn any maneuver, only execute a few of them, have full BAB, and execute the ones he wants selectively but has a passive recharging mechanic that's more predictable than the crusader. I had actually thought of several unique mechanics but I was worried that it would be too powerful if I added extra stuff.