Everything you need except for the VRCSDK is contained within the package!
All our uploads can be imported into the same project! You don't need to import the VRCSDK every time. Just be sure to import the shaders and Dynamic Bones only once! If you're not sure, just use seperate projects, that works fine as well!
Look here for a video on how to import the avatars:
(Scythe fix) Ok i used it for a day or 2 now, a guy figured out the problem just by looking at it, then i did the rest from there. The scythe materials are incorrectly configured in unity (sort of), to fix the look of it set "outline mode" to "none" for materials t002, t004 and t006, do that and people will not even notice it has something wrong.