I have even saved the project to a temporary filename, and then deleted all the tracks except for Bass and AD2.  When I try to play it I get pops instead of bass and drums, and the pops continue even after I turn the engine off.  CPU usage is barely cracking above zero and I have tons of spare ram.  Anybody else having these issues?

Try disabling the 64-bit double-precision engine. I reported an issue some time ago about getting meter-pegging pops from with an auto-stretched section of silent audio. I only ever saw it in one project, but that project still does it in Platinum unless I disable the 64-bit double-precision engine, but it stops with the transport.
 
If you're still hearing noise when SONAR's audio engine is off, it would seem that something's going on with your interface driver or some other app sharing the driver.
 
 

I recently got myself a new monitor (4k)- I had to update the geforce drivers to see it's 4 k resolution. Thereafter I started hearing snap crackles and pops (no rice krispies though). When I checked my contril panel/system device manager I saw the hi def audios were reactivated- after I disabled them the pops disappeared. 

Yeppur!  Disabling the 64 bit engine eliminated the popping, loss of audio on audiosnapped-clip.  Horrible noise extending beyond when audio engine turned off also gone.  Works fine with that checkbox NOT checked.
 
I've run into this problem on at least one other project, but can't remember which, and don't have time to experiment.