Thanks for a fascinating post (along with the subsequent discussion).
I'm sure you will figure out what is best for YOU to garden in, though I for one would take Carla's advice to heart on this subject!
I am benched along with you. I feel there are different times and places for skirts and shorts. I prefer skirts aesthetically, but they are hard for me to walk in, as I've tried multiple solutions to "chub rub" and not found any good ones.
OTOH, shorts are the first items I size out of, even when my weight just shifts around (a pair that looked fine last summer will still fit but look off the next.) I am seeing a lot of looser shorts this year, since other bottoms are looser too, so I'm wondering if that's a better investment. Heck, this year I can even work in them, since no one will see me.
Also - even though I'm sensitive about cellulite too, I find shorter shorts more flattering on me in most cases, which was an interesting discovery a few years ago. I think it's because my legs are long for my height. I won't wear skirts that short, though!