As to your first question I have a BERING jacket, full armour loads of padding and even a detachable winter lining, but it does have loads of openings that unzip to let the air circulate so if it's hot you can at least keep cool(ish) while moving, I worked in the Ambulance service for 30 years and have seen the result of road rash, believe me I would rather be hot than have someone scrub the dirt and grit out of my wounds if I fell off, so if your ever tempted to go without your jacket ask your self "Do I like the idea of having my raw bleeding flesh scrubbed with a nail brush and then covered in antiseptic?" if the answer is yes then go for it, if not then wear you jacket even if you feel like your sweating buckets.
I don't think there is any reason for the side stand to be on the left, other than as you suggest, that it has always been there, someone will be along shortly to tell both of us why it's there and how come we didn't know!!