The i7 should work well as a BOINC cruncher even though it is a few generations old. The amount of RAM might be a bigger issue for running multiple all threads at once when you compute some of the more memory hungry projects.
I try to be part of a few BOINC projects at once to buffer against work shortages and also to have a spread of GPU and CPU projects.
VirtualBox with BOINC needs a bit more user intervention and micro-management so it is best to leave those projects until you have been on step 5 for a while and want to spice things up a bit.

I hope you enjoy the ride.