Question 1: Can KoTB be played with a party of 7 (using the front-end utility to increase the PC count to 7)? I tried a party of 7, and had over 55 saves. I cleared most of the spider forest and it's lower caves. I returned to the town and read the quest-board which started me on the 'Missing Adventures' quest. I got in 1 very difficult fight, so I headed back to the keep. I get a CTD when I go into any building. I did use the console around Save #53, so, I went back to Save #52, same issue; I went back even further, same issue. Next, I created a new party of 7. I bought equipment, did NOT use the console, and hit save planning to search for the hidden ladder north of the caravan. I load that save which immediately CTDs. Note I am not using Quick Save. I create multiple saves since I am paranoid of a corrupt-save-issue which I apparently encountered. Originally, I uninstalled TOEE, re-installed the game, patch 1 & 2, the 'patch-2 no-CD crack' of an appropriate size, installed co8 5.6.0 (from the sticky thread link), and installed KoTB (from the sticky thread link). I've only activated KoTB since I followed this setup. Regarding the experience: I was enjoying the KoTB expansion aside from getting poisoned (spider), and paralyzed (ghoul), and poisoned (snake), and paralyzed (carrion crawler)... that was a bit annoying. Plus, everyone I've talked to in town appears to be evil (a lady in red, and a guy who wanted spidersilk for caring for dead)... maybe I just haven't encountered the non-evil folk yet. I do enjoy the added equipment (like the tower shield). Question 2: Does 'everyone' need the climb skill, or is it good enough to have one climber in the party?
You should give the Climb skill to anyone you don't want to be injured by not being able to climb. 7 party members should work fine in KotB. The save corruption is odd. If you had a bad proto in there, it wouldn't normally affect saves where the bad proto was not introduced. Your setup sounds good. Did you allow the KotB module to activate fully (waited until you got the "it's done" message in the front end utility)?
I did wait for the activation to complete fully. I managed to find a similar report in the 'Official KotB Demo Bug List' thread:
There are some CTDs plaguing the demo - sorry to hear they got you. I have made some changes which I think fix them and cannot remember the last time I had a CTD in my game (and I mod/play daily) so hopefully I am on top of them.