Getting old sucks, doesn't it? Well glad to say someone a couple years older than I still hikes out there
I don't find many who fit that description on my hiking.
You've got a wide range of effort in those hikes you list. Did you get to the mouth of Redwall? It is straightforward but a decent haul up the fan from pavement. And you're right, if in doubt, avoid canyons in thunderstorms! Are you going to get to Palmer from the mouth of Titus, or walking up from the pavement? We did it from the mouth, there's use trails pretty much all the way (just don't get suckered into following the main use trial into Fall Canyon, and when you cross the Fall wash, try to first eyeball a rock cairn on the other side showing you the proper place to exit).
Mummy isn't much more than a stroll. The Crack is surprisingly nice, again not a full day, but a bit more effort than Mummy.
I do not know of a slot in the Kit Fox hills, but I can recommend a loop there. If you park by the "historical wagon wheel marks" interpretive marker (WARNING: was this still there last time I went by? Not sure) you can travel up that canyon till it ends and takes you up to the flats pf desert pavement above, then head north, pick up the old road from Rhyolite, and down the larger canyon - which still has some of the poles from the Rhyolite - Skidoo phone line. When that hits pavement, just turn left and walk 1/2 mile or so back to your car. This was the very first hike I did out there, carrying my then 3 1/2 year old daughter, decades ago
If the interpretive sign is indeed gone, it's the first canyon south of the telephone line canyon. And that canyon empties out just where the dirt road to the Stovepipe Well site is - no surprise, it was all part of the same road down from Rhyolite.
I highly recommend doing your Redwall hike on a sunny day. The sunlight really brings out the amazing red colors on that canyon, the light in there makes it one of my favorites!
Anyway, have a great trip, and keep on hiking!! 2020 did a number on me, but I feel "young for my age" again after a summer of hiking this year.