First off, congratulations on beating KBTL with a pretty high score. I believe you could have done it a lot faster had you known that there is a detailed quest walkthrough at the GameFAQs website; as with all speed runs in KB, proper planning on how to accomplish the quests in optimal sequence is key.
Having said that, below is a link with regards to the optimal route for KBAP:
http://forum.1cpublishing.eu/showthr...light=shortest
If you really want to target a pretty high score in KBAP you have to guarantee yourself an abundance of Ancient Knowledge scrolls. Just do a search on the forums regarding this topic, as well as the KBScanner.
As for your main question, there are a bunch of changes in game mechanics, but none that directly affect a high score attempt (except for the wanderer scroll Ancient Knowledge). You said you were going to do an initial playthrough, so I'm sure you'll find out about these changes then.
Good luck!