I have a few tips:
A: If you want to make a very detailed adventure, but the complexity meter might kill your idea,try making static objects-things the player won't blow up/examine/give something to- into blue gates. Blue gates cost half the complexity as the building/object you disguise them as,saving a huge amount of complexity. Take my newest adventure,for example:
It is very well detailed,yet the complexity meter is nowhere near full,thanks to the blue-gate trick.
B:Somethings your creatures/captain can fall into buildings. This is a glitch with the building's load time. To fix it simply place an upside down jump pad all on the surface of the walking area, and set them to invisible. Now you can walk on it without issues!
C: I found out a neat way to make moving doors,look:
How to make doors that open in 1 act
Click for video!
1- You can't get Advanced AI on vechiles,but you CAN make them follow a creature with Advanced settings. In short,the creatures are set to:
Wander radias is set to the lowest possible,it prevents them from animating(and going out of sync with each other) though sometimes it still happens. They MUST walk in a straight line in the exact opposite of the doors or the doors will not open like doors.
2- The doors themselves are actually vechiles,as mentioned above. They are flat,though they do,unfourtunetly,float. There are multiple ways to go around fixing that. one is to do #3,another is to make a pit in the ground so it seems it's not floating.
3- In this example I used blue gates disguised as buildings(as actual buildings would get nowhere near the doors) and made them float so that you don't see the doors float.
I also recently figured out that if you make two vehicles small in the EDITOR,then place them together in the adventure very close to each other,then edit them in the vehicle editor,you can make them as large as you want without them being too close to each other. As in,they can overlap each other but they aren't "conflicting" with each other and turning red.
EDIT: Oh,peli,you already knew trick #3. Though mine has more option potential...