1. Only two asymmetric algorithms are widely supported and almost universlly recommended, RSA and ECDSA. Compared to RSA, ECC needs smaller keys for same security.

2. I did that couple years ago already, I think it actually was 521 bits, the best one recommanded by FIPS at that time. The hardware has no relations to FIPS, it's not even _that_ expensive and should contain no secret data. I just saw no reasons not to implement the best security available: development time is not affacted by the count of these bits.