Paul. also consider the classic Leica table top tripod. With the medium ball head you can put the three legs on your chest and still have the camera high enough to use the finder. It allows you a "stable" platform without having to drag a full sized tripod along. The ball head will allow you quite a flexible movement when needed. Folded up it can easily go into a bag or even a largish jacket pocket.
As for getting old, it does beat the alternative! I have severe nerve damage in my leg and some in my hands, but they have not yet translated into tremors. Biggest problem is fatique. When you literally cant feel your feet, walking becomes a bit of a guessing game! Even surfaces are fine, grassy fields a disaster and every architect who insists on polished marble floors should be made to walk across it with shoes that have been soaped!! Stairs without handrails are a no-no - I will not venture down or up them! The biggest bugger of it all, the whole thing was caused by medication, Thalidomide as that was the "last chance" medication when I was diagnosed with Multiple Myeloma in 2001 ( a form of bone marrow cancer - incurable, but kept in its place with various chemicals at the moment).
I have this appreciation of parking meters. When my legs decide to veer off - I can usually grab hold of one and correct the drift! It also gives me plenty of excuses for visiting cafe's and sitting down.
With any illness, the trick is to work within the limitations imposed - and have the right to occasionally be pissed off about it.
When I was diagnosed, my hematologist/oncologist told me that the two most asked questions asked were "How long do I have left?" and "How do I avoid paying taxes for that time?". I always felt that it was the right spirit.