Yes and no.

In general, custom races made for D&D 3.5 will work just fine in Pathfinder. Nothing really major changed as far as races are concerned between 3.5 and Pathfinder. The biggest thing to look out for is that Pathfinder no longer has the concept of level adjustment, so there typically needs to be some houserules to allow more powerful races, if they'd have an LA. You also want to make sure that any races with an LA of 0 have a total of +2 to ability scores, rather than +0.

My previous DM had a houserule that worked pretty well for this. We used point buy for stats, and he ruled that for each +1 LA, you lost 4 points from your point buy total. Since we only had fairly small LAs, this worked pretty well.

That said, the race that you linked is pretty powerful. It has extremely favorable stats, flight, DR, a suite of resistances, smite, SR, change shape, and a couple other powers. I'd give that race an LA of +4, at least. I would not suggest using that race in a Pathfinder game, unless everyone is playing a similarly powerful race, and you're comfortable with a high-power game.

There is no "generic" answer, like everything else about D&D it varies by game world.

In Paizo's Golarion campaign setting, then your key references are the Second Darkness Adventure Path and the Into the Darklands campaign setting book. Generally they keep as slaves "whoever they can get their hands on that is useful and tractable." This includes everything from troglodytes to other drow to surface folk to driders to dark creepers to "balor-possessed greater water elementals" (all these are listed as slaves in that drow city you're talking about).

To drow mores, anything and anyone who is not a drow is a candidate for slavery. Their word for servitor is anquestra, while their word for outlander is jenanquestrok, which means “not yet a slave.” Sentients that are spoils of war are always considered slaves, especially if the purpose of the war is to gather more servitors. Similarly, non-drow trespassers can be declared anquestra, and this can happen even to non-drow offered protection from a noble house, should another noble house want to enslave them.

In the drow culture part of The Armageddon Echo it says "drow don't enslave other drow, but some do become servants" and then in Endless Night it refers to drow slaves about a zillion times, who seem to meet the standard end of slaves, so YMMV.

If you want a list of other darklands races that might be good candidates, consider checking out the Pathfinder Wiki's Darklands and subsidiary entries, or the list of creatures whose habitat is underground from the d20PFSRD.