2
BIP 32 allows me to derive keys based off a root key pair, and all these keys will be on the secp256k1 curve. That means I'll be able to use BIP 32 for other coins that are also based on your curve.
Is there a list of well know coins and the curve they are based on? My spot check shows that most seem to be, but I'm looking for a more comprehensive list
5
Bip-32 allows me to dereive keys based off a root key pair, and all these keys will be on the secp256k1 curve.
This is actually not true. The BIP32 proposal simply states that (emphasis mine):
In the rest of this text we will assume the public key cryptography used in Bitcoin, namely elliptic curve cryptography using the field and curve parameters defined by secp256k1
In reality, it can be used for any curve, as evidenced by the fact that both Monero and Zcash support BIP32 backed derivations, but use different curves.
If you wish to see a list of coins that follow the BIP32/39/44 system, you can check the coin type list maintained by Satoshi Labs at SLIP-0044
