First off, I'd give Axiom a call... they may really go above and beyond with helping you before you start having to tinker at all yourself.

And no... the only problems you should encounter with using an underrated fuse would be it blowing prematurely (insert joke here, Peter!) or if the original fuse was a fast-blow (insert joke here, Peter) type and you used a slow-blow (and here) type. It may not have opened the circuit fast enough to protect from damage.

Bren R.