I know downloading here on SimTrop can be cumbersome, to say the least. Ive been doing it for a few years now. At one point, it took me over 2 weeks to find all the dependencies and get ALL like 300 of custom lots to work properly.
To answer the original question, no, there are no dependency packs that house any % of the needed depnedencies for "most" of the custom content.
The best tip I can give is erase all of your customs, start over from scratch.
Download each lot. Read the "readme" and download the dependencies as you go.
If you dont want to do that, than you will have to do what I did and read all of the current "readme" files you have now, and start downloading....