Yeah when I was reading this I raised an eye brow, I've always been able to edit, delete, add tasks but I use the Pro Edition.
Out of curiosity I downloaded the freeware Home Edition and indeed you can't edit tasks at all. Different than the Pro Edition which I've always been able to edit tasks. You can always remove tasks and do it manually as well.
Don't know if sale is still on when you get this, HDS does a few sales throughout the year but I'd recommend waiting for the sale.
Comodo made an OEM of Rollback Rx, it's callled Comodo Time Machine. It's not as good as Rollback Rx imo as it's based on Rollback Rx version 8 (they're now on Version 10). but hey it's still an option
Yeah Rollback has been (surprisingly) the best tool against ransomware. I was infected a while back. OS was compromised, my disk images were corrupted, the only thing that was able to restore my machine was Rollback! Because it encrypts the program and data it's protected from attacks.
Either way, food for thought. Your config is pretty good, I just recommend having something else to back up the machine that's a bit faster. You can still do without but of course there's a bit more of a risk factor involved there.