Mr B, I can't be bothered to read the entire thread again either to answer your questions but I would applaud your stance on avoiding the XPDR deficient aircraft for X-C solo.
V wise IMHO.
I once rented a XPDR-less rustbucket C152 (come to think about it it had no navigational equipment either (No GPS/VOR/ADF)) and got totally bloody lost for several hours while trying to find Badminton in fairly mediocre weather for the princely sum of £350. I never did get there!
I had had my license a while and planned the route out to perfection but the first CB I had to fly around made all the chinagraph planning go right out the window.
I didn't cause any infringements that day and ATC were polite, patient and as helpful as they could be but it was an expensive lesson.
Life is too short to fly poorly equiped aircraft (and pay through the nose for it).
SB