First of all, why you need to create so many devices? What's the background context behind your request? Perhaps there are other options available.
Next, all you need is a loop of some kind to run the same command on each entry in turn. If it's a simple sequence of numbers, I'd personally recommend a c-style for loop
. If the sequence is from a file, then use a while+read
As for the last question, I have no idea personally, but I imagine it would probably require modifying and recompiling your kernel in some way.