Hi ... doesn't really mater what ripper you are using, but I agree with the sandboxing approach that you mention. Just not to your SSD necessarily or if you do for speed or simplicity move, not copy, the files after the rip to another "holding area.
What I do is lets say you have a mapped networked drive Z:\ . You can create 2 separate sub-directories say Z:\Music and Z:\Temp. set your import options to include them. That way you can listen, retag, and compare tags from the same artists to be consistant (linkable columns are good for this). Setting up a tagging view to include only these files is very handy. Also good to search for duplicates, and if found you generally just would remove those from the holding area path.
Also dbpoweramp has a pretty cool feature about adding custom tagging automatically at the same time as the rip. For example I use a special tag (I call it zRetag, but you can name it what want fo course). I use the Grouping field but you could use any one like genre. You can then set up the retag view based on this tag. When you are finished, you remove the tag and you could make another view to help you just move the files to the main that are verified (using the Moven copy rename tool or F6 in MC). Some people create a logical check box field for this too. Many ways to go about it. I just remove the temp tag and replace it with something else. So you have the holding area benefit, the + of being able to compare existing tags in your main library and you can take the time you need to do it and still listen to the stuff.
Of course if you decide for speed or convenience that you want to rip to your SSD, you certainly don't want to keep them there, not including the ssd drive in your import config will avoid dupes and everything too in case you copy them instead of moving them. You might want to do manual auto imports so you won't wait for some event to prompt autoimporting when using a NAS
How to make a simple question into a complicated mess huh
PS - As for the double backups I don't think it is overkill, I lost two drives during a restore once and man what a drag. Main media and a backup in a PC or NAS and the second "archive" stored separately. Making sure you backup the JRiver library backup file on both! Also think what would happen if you get your NAS stolen. ?