Submitting transactions when wallet is on client

Hi, I'm looking into using `ethconnect` to help scale a blockchain-powered mobile app more easily. Our users will be storing their wallets on their mobile devices, so the signing must occur on the client. Based on the docs, it seems like `ethconnect` is designed for a usecase where the `from` address is in a wallet on the ethereum node. I'm curious if we can expand its functionality to our usecase:
- Can we query `ethconnect` to find the nonce the transaction will eventually be assigned?
- Can we submit raw signed transactions through `ethconnect`?

*(Unless I just didn't understand how to do this from the current README, this is probably an enhancement.)*