As for the 'why not' questions:

Rubbing alcohol contains water. As much as 30% of the bottle can be water. Water dosen't evaporate to well when mixed with epoxy, so you'll get little 'pockets / bubbles'. Also, thinning epoxy too much will also leave little 'pockets / bubbles' in the epoxy, and it'll be like foam, waiting and wanting to soak up any oils.. Also, it can greatly increase the cure time, causing a 'rubbery / gummy' coating that never seems to fully cure..

Methyl Hydrate or Denatureds Alcohol evaporates at a high rate (and contains virtually no water). And you only need a few drops per ounce of mixed epoxy. (I remember erading about someone using a 50/50 mix of alcohol to epoxy.. Big no-no!)

Heating is and always will be the best way to thin epoxy. heating the bottles in the nuker for seconds has worked (so I've read..) and the bottles in cups of hot water work teh best (known from experinece) but use long cure times for the reasons stated above!!

Plan to 'fuel proof' outside on really hot days! This time of year is perfect! PArk teh bottles in the sun for a bit, and the plane, then go at it!

(I learnt my lesson when glueing in my hinges, they seemd to cure prematurely. I was installing them on a really hot summer day! +30°C. On day , I'll pull off the offending aileron, and re-hinge it..)