Using the RPC, I want to import and delete wallets programmatically without messing with the filesystem. Anyway to do this?
You shouldn't do this. There is no reason you should manage wallets on an internet connection device, let alone one with open RPC connections.
it’s come to our attention that some individuals have been bypassing the built-in security that has been placed on the JSON-RPC interface. The RPC interface allows you to send transactions from any account which has been unlocked prior to sending a transaction and will stay unlocked for the entirety of the the session.
by default, RPC is disabled, and by enabling it it is only accessible from the same host on which your Ethereum client is running. By opening the RPC to be accessed by anyone on the internet and not including a firewall rules, you open up your wallet to theft by anybody who knows your address in combination with your IP.