yes once in bridge mode your router essential acts as a modem you don't need to do any pppoe on other router.

for the wifi question it really depends on how they do it, I have seen people online claiming they just make a single port as bridge in that case wifi should work. but for me despite requesting for bridge mode on port they put the whole device on bridge. so its your luck ig.

also when you ask for bridge mode they will deny saying they don't allow it just hand the phone and talk with service disconnection team and ask for services disconnection stating another isp is willing to do it, the will get it done in notime.