[Loadsmasher]

I faced some of the same issues as you've addressed and have a couple suggestions.

1) Sprints, Sprints, Sprints. It seems counterintuitive that short distance improves long distance, but it does work.

2) Run barefoot. If you can find a place to do it. Nothing will fix heel striking quicker than taking away all that space age foam and rubber. If you can't find a place to run barefoot, Vibram makes some shoes that are a close second.

3) Run almost every day. Switch it up with long and short distances, quick and slow paces. Build up slowly to prevent injury.

That's my .02 Baht