We'll do our best to disappoint your cynicism.
We currently have about 150 feats from the D&D 3.5 SRD implemented, almost exactly as they appear in the ruleset. We also add some new ones whenever appropriate (if they would fit to a certain prestige class or just a culture of our world, if we have a good idea for an addition to the ruleset that would make sense for our setting, we'll put it in).
Attribute generation is done similarly to KotC, with dice rolls + minor modification/point swap. We also let you decide to use a point buy system if you don't want to autistically re-roll until you got all 18s (which you won't cause our algorithm isn't pure random, you won't end up with all stats being the same), but of course point buy won't give you as interesting/varied results as rolling.
We haven't yet planned any house ruling for the other basic classes, but we're doing some with prestige classes and how they work.
It won't be a strict "once you enter a dungeon, you can't leave until you're through" system, but a case by case basis of various dungeons that all work differently. Some dungeons might have a one-way entrance and the exit is somewhere else, in some you'll be able to enter and exit whenever you want, others might lock the door behind you and you'll have to find a way to open it again, etc. Resting within dungeons will work in a similar way to Dark Sun: Shattered Lands and Knights of the Chalice, with fixed resting points within the dungeons where you can rest and restore your spell slots. The locations of these are, of course, designated by the level designer, so if we feel particularly evil we might give you a hard dungeon where the door locks behind you and the first resting spot you come upon is all the way down on level 3. If we feel particularly generous, we may give you a dungeon with a resting place right next to the entrance, and you can also leave whenever you want. You know - variety. Variety is the meat of a good RPG and ideally, every dungeon would offer a different experience to the player.
We could theoretically implement the Pathfinder rules since they're also OGL, yes. But most of our team are more familiar with D&D 3.5, and some of us also prefer D&D over Pathfinder, so that's what we're focusing on.
Doesn't mean we won't add some elements of the Pathfinder ruleset if we think they'd be a good fit for our game.
But I know that you're a massive Pathfinder fanboy, so you'll be happy to hear that we're aiming for a high degree of moddability. If you want to, you'll be able to add classes and feats from the Pathfinder ruleset to your own module. Heck, if you say "most of your homebrew rules are shit", you can change them to be closer to the original D&D rules, too. When it comes to modding, we'll try to give you as much freedom as possible, which includes being able to modify the classes, feats, races, etc to your heart's content.
