Is there any particular advantage (other than the promised income) or disadvantage to accepting Nalia's offer to let you take over control of de'Arnisse hold after you clear it out?

I'd have to say no to that, except for the De'Arnise Hold quests that come with you being owner of this Stronghold. I have yet to go back, I have no reason to go back because I simply don't care about it.

I fought for it, that's it but it doesn't feel like I own in. Why is the secret door no more? I didn't cover it up when I left.

Why did the Golems leave De'Arnise Hold? I never commanded them to.

To me, it's a waste.

Syl...

I kept it so Nalia didnt run off... after that quest i never needed money again.. so it didnt really matter to me much either

I would have to agree with everything Sylvus said above.

Interesting, I played this quest my first time thru BG1 and now on my second time as well. I've enjoyed it. It's been a great place to rest when between areas, a place to stash extra equipment that I may want later on in the game, It produces gold every week or two, there are side quests related to it, eventually you have your own Cleric there with all the Temple services & potions & scrolls, you get attacked by the Roenall's...

I've always liked the keep. It would've been nice to have the Golems. But I always killed them when getting the quest to begin with -for the XP and the challenge.

The secret door stays there... you may just need to move the right character close enough to detect it. I use it for entering each time -I raised the drawbridge and kept it that way. (I know, paranoid, but the first time thru I didn't know *what* was gonna happen to MY KEEP!)