So you would be ok with running races being won not necessarily by the best runners, but by the racers with the best tech? Would you be ok with any of these? How about other sports, like jumping events, or basketball? I don't see anything wrong with rules limiting technology to keep a sport as it's supposed to be.
In the first one: So long as they are available to the general public (easily!) and meet the other guidelines: Sure. They are still obviously shoes.
Runners would choose which tech they want to go with and since there are price restraints and rules about them being available to everyone for months, I don't see an issue. The sport is going to look the same to everyone else. It isn't going to change anything: It isn't like professional runners are going to be using cheap, bottom-of-the-line running shoes any more than a swimmer is going to wear baggy swimming shorts. I don't mind customizing shoes based on activity and weight and so on.
In your second example, he isn't testing shoes. His shoes are still on his feet as he uses the things. Obviously those wouldn't be left in running because you aren't really running. I'd understand much more if we were talking about amputees, and then it would really depend on how it compares to two-legged folks doing things (I don't know the advantage/disadvantage compares here).
Make the rules something along the lines of making sure that the shoes are available to all:
* Must be commercially available to all competitors
* Must have been available for 6 months and have had minimum sales of say 5000 units more than 3 months ago
* Price must be below $250 to allow all competitors to buy them
* Some limitations to customisation