Hi Pinemarten,
Welcome to Boinc & the team!
Yeah there are (at least!!) two types of Intel dual core. I'm pretty sure you a
hyper-threaded processor, rather than one with two separate cores. But it still acts like it has two cores, and BOINC will process two work units at once; in Task manager, the two science applications that are running will each show as using about 48%, if you have no other intensive activities in progress. (The science apps are what do the crunching, not the boinc.exe and boincmgr.exe programs; the science apps will have long names in Task Manager, like the Einstein one is now 'einstein_S5R2_4.xx_....'.
If processing two WUs at once causes overheating, there is a Boinc manager Preference to throttle the CPU back, say to 90%. On the same page, you can limit the number of 'cores' that Boinc uses, in your case to 1. (Again, your HT machine is seen by Boinc as having 2 cores, even though it doesn't

) This shouldn't be necessary though, as Boinc is designed to run at 100% in each core, but at low priority, so that there will be almost no noticible interference with your other work.
As far as projects go, the beauty of Boinc is that there are so many types to choose from, and you are free to run what you please, at whatever share you like (although differing deadlines and WU lengths can sometimes constrain this a bit.)
That said...
Math is almost universally regarded as abstract and impractical, and when I studied math, most of us regarded 'number theory' as especially abstract and impractical. I mean, if
math majors see something as unconnected with the real world, it must be doubly so!
Of course,
now the study of factoring primes (an essential subject matter of number theory) is at the very heart of cryptography. The formulas which tell you how long a given encryption scheme will take to break using brute force are exactly the kind of number theory topics which put me to sleep. Etc.
All a long way of saying: you can never tell with mathematics what will turn out to be useful eventually,
As far as chess360 goes, again, no one makes you run it, and if others want to, why not? I mean, computer games take huge numbers processing cycles away from the 'approved' science apps, so should we make Grand Theft Auto a crime to play if you've installed Boinc?
I'm guess I'm being pretty thin-skinned to take your point about taxing chess literally, my apologies...