If your VC has gotten "stiffer" (and now fails the 2x4 @ idle test), then yes .. you could most definitely be causing damage to your transaxle's R&P.  I've seen clear evidence of this over the years.

Decoupler installation isn't that difficult of a DIY project.  It requires dropping the front of the trans just a tad.
 
> Hey, when I drive my syncro on the freeway, the front wheels
 are binding up
 when  I try to park. I don't have a decoupler. I'm
 trying to figure out if
 this is an emergency where I risk frying my transaxle, or if
 I can get away
 with driving for a while. I don't know how feasible it is to
 install a
 decoupler myself in the street. <