Thanks.
I did since then find out a few more things...
One) If you set #LoadOnDemand to TRUE obviously the addon won't load automatically...
Dôh.
Two) If you set it to FALSE, it will load automatically and error message will pop up for missing dependencies.
Yay!
What doesn't help is that there seem to be multiple versions of the same libraries included in various add ons (nor do all FuBar plugins carry with them the complete set of libraries they need to run).
So.. I think I got everything now. Except for one thing... Is there a way to manually load an add on if #LoadOnDemand 0?