Aribeth wrote:Can't rest, only wait. And by waiting you can't replenish spells slots. Or heal.
If you can't actually rest then something is wrong (reload and try again or start new). There is no place in MOTB where you can't rest (that I remember, and I've played it a LOT). HOWEVER, depending on the threat level, your rest will often be interrupted before you finish resting (and replenishing your spells).
Note: there is a condition that won't let you rest: when enemies are nearby (..but you should get a notice of that). In that case go kill them and try again. Another potential condition is when you have a lingering area effect spell that continues. For that, just wait it out until it dissipates.
For a Sorcerer in MOTB I tend to prefer the spell Planar Binding, Greater (particularly with a Neutral (NOT Good or Evil) alignment Sorcerer. It's the longest duration higher level summon in the game. It also can be used (instead of summoning) as a means of paralyzing Outsiders - which is useful in MOTB (..particularly at the end). Always use Mage Armor or Improved Mage Armor on your summon and add-in Spiderskin if you have that. Again, more of a distraction than a means of damaging opponents.
Here is a build I did for the OC and MOTB: http://nwn2db.com/build/?129805
Note the "Notes" section when you scroll down the build page. Not only is there a full listing of spells (with most of the reasons why), but it includes an item listing. You can quickly craft a level 20 character with most of these items via Vordan's Hero Creator (do a web search on it), export the character with them, and then use that to start playing MOTB.
In the items section I have spec'ed the amulet: The Scarab of Greater Protection. This provides immunity to both Death spells and Level-drain spells and effects. (..it also adds-in 20 spell resistance.)