I recently added Superlink@Technion and found that it would not run on one of my machines because:

RAM: 1GB of RAM is suggested, as the computation typically requires up to 700MB of memory.

I also added climate prediction and found the the WUs were too huge for me to accomplish while crunching other projects on computers that are only on eight or so hours five days a week.

I couldn't find a list of project requirements (RAM, HD, WUs, etc.) on a single page (Wiki, BoincStats, etc). Is there such a list?

I know there are minimal requirements for Boinc, but I'm looking for a list of requirements beyond that.

Honza maintains a table of BOINC project requirements on boinc.cz.

I understand the faces, checks, and "x"s in that image, but what do the "6"s mean?

"6" means native support of x64 platform, ie - it sends real x64 aplication, not fake x64 (renamed 32-bit apps like BOINCSimap or Rosetta).

See this thread on BoincSynergy for more explanation.