Forum:Something about Chaos Emperor Dragon - Envoy of the End

Hello, I need some help with this pleaseee:

Player A has 1100 LP, a face up Chaos Emperor Dragon - Envoy of the End and Player B has an 500 LP, Ancient Gear Knight equipped with Ancient Gear Tank, Ancient Gear Golem a face up Geartown and a set Starlight Road.

Is Player A turn:

Player A uses emperor dragon effect> pay 1000 LP (remains with 100LP)> and tries to nuke the other cards. Player B activates Starlight Road, trying to negate emperor dragon eff and summon Stardust Dragon.

1) Player A claims that he has Priority on his turn so starlight road cannot be activated. Anyone can explain this?

2) Even is starlight road isn't activated and player B's LP reach 0, ancient gear tank goes to graveyard therefore inflicting 600 damage (player A's LP reaches 0 too). The duel ends in a draw?