I would try to bend the tips or Dremel them down. As for the vinyl - i just happened to have some white vinyl laying around but go on down to a JoAnn Fabrics or similar and you'll have plenty to choose from.
I figure if I Dremel them down, I'll just wind up making them sharper in another direction, unless I can round out the tops. Easier to put some rubber plugs on them. They don't respond well to bending, that's for sure. Not sure I want to stress them either..
Ahahaha - I already went to JoAnn and found a good piece of vinyl, but figured I could do better on Amazon. And I did - both the foam and vinyl were half the price of their equivalents at JoAnn (I had looked at the thinner vinyl there too), but the vinyl listing at Amazon failed to note thickness. Only one lists itself as 32oz.