Thanks for all the help. The toe raises that a couple of you suggested feel fine and I'll be doing those. I also took up the stretch-one-toe-at-a-time routine that was suggested, it actually feels much better and more controllable than just pushing all your toes into the ground
Ronin: Yes I don't have problems with my toes during front kicks, it's when doing roundhouses with the ball of my foot that my toes take a beating
I guess the flexibility needed in your toes is pretty high as you gotta be able to pull them up to at least vertical from the ground when standing.
Anyways, thanks for all the advice, and I'll be sure to post my progress