Hey Silverblades.
I wanted to first start you off with the required processes and information regarding Palemaster. Take a look at this link and do click through to read up on the Palemaster a bit. http://layonara.com/nwn/prestige-class-submission-requirements
Additionally, you'll need to post in the CA for approval prior to requesting a GM run you anything for the actual Palemaster PrC though if you have some development you'd like to do -before- that to get the ball rolling, you should contact the GM of your choice in their CDQ thread and either openly or through a PM share your details so you guys can talk things out.
Regarding CDQs, the process and conditions have changed since you were here last so you might want to read over this thread as well. http://layonara.com/nwn/character-development-quests
Regarding gap in lore-knowledge, that's not an uncommon problem. There's a host of options for you there and you can really get as creative as you want there so long as you don't go crazy with the details (i.e. don't decide that the character went off and killed a known villain to explain the absence or something along those lines). If you can keep it within the realm of your character's current power level that should do fine. Other options that might work are things like, taking ill with something horrible that caused a lot of down time, having gotten lost and decided to stay lost for a while, etc. If you are unsure about the story you'd like to go with here, feel free to snag a GM and run it past them for a second opinion.
Finally the spell lexicon is available at this link: http://layonara.com/nwn/encyclopedia-of-spells Check the menu on the right to search as you like, or you may use the search box in the upper right hand corner of the page to search for a specific spell if you need.
Hope this gets you started. Feel free to follow up if you have more questions.
~row
(Also, I moved your thread to the correct forum and deleted the extra copies of the post)