Hi there, Shmuel :)
First of all, my edits to the cheatsheet weren't wiki tricks; they were simple html tweaks, but sure, they can be of use as well!
Second, about the templates: indeed, we need a better way to organize content here. I could bring some know-how from my Wikipedia experience, but honestly my biggest hinder right now is time. Please write me whenever you have any question or something planned for the wiki, as that will keep me coming back :P
Anyway, regarding specifically the suggestion you proposed for linking to geni (a template), I believe the best option would actually be to add geni to the wiki's sitematrix, so we could link to pages there using simple markup like [[geni:123456789|my profile]]. The template kinda works, but in reality is a workaround.
I do have several other ideas for the wiki (most of them are in the todo list). Perhaps I'll ask Noah for some privileges so I can at least edit some configuration files.