Well so far, so good. I've rebooted my computer a few times, and EasyTether is still working OK. Don't know what happened with the previous install, but this seems to be working.
I appreciate the suggestions on other options. I did consider PDANet, if EasyTether doesn't pan out. But EasyTether is 3X lower cost of PDANet, so that's what I would rather go with. (EasyTether is free now, but will still only be $9.95 with https support. So obviously a better deal compared to $30 for PDANet.) It all hinges on how stable EasyTether is.