1. Currently, the PIVX Core wallet is needed to SHIELD/DE-SHIELD PIVX, this is done (from my memory) by simply generating a "Shield" address in the Receive tab, copying it, and sending your PIV to this address, it will be converted and sent back to your own wallet as Shielded PIV, the same process is used for de-shielding: copy a "transparent" address from your wallet, and send Shielded PIV back to yourself.
2. This is not currently possible, but on the development roadmap.