for all the hassle, its probably better to stick with your mouse.
I use F2 to rename clips. I also do what you do (Digitize old recordings. 4TRK cassette , Reel, Records, EXC).
I establish a base when the files are first imported. That way when I drag them in to Sonar they are Pre-Named.
I also use a Mackie Control (MCU) which allows me to quickly select clips. This alleviates the "Click here, Click there, Click here" issue. Are you using a control surface of any kind ? if you are not, it would be a great investment. especially if your doing work in bulk.
Using the inspector and F2 will get you half way there.
I've tried a lot of different things myself. there is no easy way around it.
I should also note, I probably don't do as much work as you. (not 1000's of clips)
But because my machines are a bit of a rarity (Tascam Studio 8, Tascam 488, Sony TC630, Multiple brand 4TRK cassette) I get a work. The thing is having the machines, but the most important part... having the machines that work with quality results

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Im sure you know what I mean.