Improvements Needed:
Things that need to change with Oathbound (IMHO, of course!):
First of all, bad decisions/game design. Yes! There are some! As one example, any Prestige Class/Race which invalidates a large portion of a PC is bad, IMHO. The Stalker PrC's ability to disappear while in the city seems to do this... Regardless of the number of ranks in Spot, you can never see a Stalker? That sits very poorly, with me (especially since my PC has the skill maxed out, and feels emasculated enough)! You may disagree, but I call that bad game design! (Yeah, in the good ol', skill-less, 1e days,
Invisibility only gave you a -4 to hit... none of this "+20 to Hide, and you must beat the DC by 20 or more to know exactly where the Invisible creature is located" BS!)

Blindfighting reduced it to -2, as well... Paladins not being able to use their
Detect Evil class ability without losing INT points is another example.
The Setting Disagrees with Itself: This is just sloppiness, boys! In the Oathbound hardback, Israfel punishes anyone causing a Sinking with instant death. In Wrack & Ruin, IIRC, she is "secretly pleased" with it! In the adventure in the same book, I believe, we see Colopitiron requiring a promise from the PCs to return his sword to him, and then they feel all tingly, and this is supposed to be an activation of a Binding Oath spell (whatever it's called), and yet... when we go and look that up, it requires a WRITTEN contract! Also, in that same book, I believe, the PCs are exploring the maze when they come upon a light, and encounter a time anomoly to Annoxus' time, before he slew Colopitiron... but wait! Isn't that supposed to be a setting secret?!? How are the PCs supposed to know what to do, here?!? There are many more similar situations spread out through the various books (and I have barely skimmed most of them)! Israfel, etc., being able to
Teleport, while PCs risk INT Damage to do the same is yet another example.
Sodomy: Without getting into Grandma-unfriendly territory, here, I have often wondered who on the BP staff is the flaming gay (and not just when looking at Oathbound products, either - A&H gave me the same impression). While I'm sure that there is 1/2 of 1% of gamers that this actually attracts, I'm also sure that there is 50% or so that it turns OFF. Tone it down, at the very least!
Prestige Classes/Races: My Least-Favorite part of 3.xe! I want my PC classes to be pretigious,!!! Why do I have to give up a level of my class to gain prestige, and become weaker than any other PC for refusing to?!? This has long been a problem, for me. I thought the original "Buy The Numbers" prestige "races" were a kind of solution to that problem... but no more! Oh well! I guess that's going to remain my problem, as long as I play 3.xe!
The Whole "No One Can Know Their Alignment!" Thing: Boundy... and his Flock... C'mon, just admit that they have an Evil alignment, and get on with it. Unbelievable (to me) that the GM's book (O

otF) doesn't even tell the GM! How is he supposed to know how to RP the eight?!?
I'm sure there are other problems, but those are the major ones that I can think of, right now... It would be nice if some, most, or all of them could be fixed in a 3.5e update, if there ever is one!
Good luck with the product line, and I hope to see
Wi;dwood in print, soon (I have all the rest)!