I'm so glad to see you bring up the sneakers issue. About 10 years ago, I had the elliptical numb foot all the time, none of the trainers had an answer when I asked why this was happening. One even suggested I might be diabetic and to get my sugars checked. Soon after, I bought new shoes, for no other reason than that the old ones were falling apart and, voila, no more numbness in the foot.
The cardio before/after weights issue seems to be a 20 year turn around. My first gym had 2 stationary bikes, with home made rubber lined blocks around the tire to add resistance. 5 minutes to warm up was encouraged, anyone staying on for more than 10 mins, got shouted at by the owner. His theory was that this was a place for bodybuilders, and if you wanted to have a cardio workout, go do aerobics with the girls. I was there for 2 years and I still can't do cardio before weights, or even on the same day. I think I was traumitized, but I have to say, it works for me. But I really don't believe ther is a one size fits all rule on that issue.
Thanks for the tips!