[Lava]

Fishing lure? I thought maybe the Cosmic Ambergris? Doesn't work.

Candle? No idea. What I'd really like to get for that lady is a broom.

These two are actually in the same building but on different floors.

You may find these in the Orrick's Tower

Girl can't climb. No idea.

That once you can heal with magic.

Cast the Remove Paralysis spell or... there was also something else... I think... Heal and Regenerate

Bartender needs a charming employee. I waited until after Luremaster to give him the tome of Charisma. He didn't want it! (There were no dialogue options for his quest at this point either, so I thought he forgot.) After rereading the journal it said "there must be something in Kuldahar..." and I realized what to do..

Yep, and there is

There is a new potion at Oswald's.

And I'm not stealing Oswald's telescope for some bum. I thought maybe there would be one in Severed Hand, but didn't see anything.

Yes, there is a 2nd telescope in the game, you do not need to steal it And it's exactly where you said you hoped to find it, in the very last room

the Astrolabe