for the first problem - you need to kill the angel so a new one spawns, the reason is a lack of time to be able to understand how to make evrey angel spawned be effected without the other angels being effected too.
for the second problem - in the beginning i thought that i need to fix it, but decided to leave it like that for then, and then when i saw how hard phase 4 gets, i decided that keeping it like that would give a player another brief moment chance to change position, so i kept it. although i plan to ( if i come back to this game ) balance phase 4 in an other way.
i hope that helped.