‘Clearing your phone’ is not likely to be effective against it being properly compromised. The bootloader could be rooted, auto-compromising any fresh installs you do. Or there could be undocumented bugs in the modem firmware that allow a fully secure phone to be compromised over the air. If you have sufficient reason to be paranoid about being bugged, turn off your phone, and remove the battery if you can.
Yes, but at the same time, I don’t know if I can handle being fully isolated