OMG!!!
When posting on this board, PLEASE try to bring some kind of intelligence and common sense when doing so. Also, it helps if YOU bring some sort of experience and or actual personal proof supporting your perspective.
I'll try to help you out:
(1) Stretching before a race (Define stretching. Easy and or light stretching after a warm up jog is highly recommended to facilitate blood flow throughout the muscles which in turn preps the working muscles for an excessive workload which includes racing or intense training session).
(2) No pain no gain (The actual activity of "running hard" is uncomfortable and or "painful". In order for the body to adapt to this discomfort it must be exposed to it in various doses so as to acclimate to it. In the end, competitive running is and will always be "painful", the secret is to manage the "pain" and or "discomfort". You can't avoid it.
(3) The higher the mileage the better the performance (This is the only point that is TRUE, higher mileage does NOT guarantee better performance. Rather, it is a combination of mileage and quality workouts that promote better performance. What defines "higher mileage"? Each runner is different, and mileage correlating with body type, genetic ability, etc...will vary. Find what works for you).
(4) Running doubles (Again, depending on mileage requirements per athlete and quality of workouts. An easy PM recovery run after a tough AM workout is very beneficial to purge excess lactic acid from the muscles, including massage and hydration. Elite runners who double up with two hard sessions a day should be aware that these are not to be done frequently, and if monitored properly can be beneficial. The more work that can be achieved without compromising health is the whole point of training and thus performing at a higher level).
And yes, my above recommendations have been tried, tested, and proven successful at both the national and world class level.