No, as already stated here in the thread, singularity is caused by axis 5 being near zero. If you only change axis 4 and 6, you don't change anything at axis 5,so the singularity problem won't vanish.
Totally agree. Said in other terms, singularity comes when J4 and J6 are alligned (nothing to do with their angle values), and this occurs when J5 is near to zero on linear movements.
Keep in mind that movement from P1 to P2 normally starts, but singularity can occur in the middle of trajectory. This is normally solved modifying the gripper giving it an appropiate offset angle on its basis (lets say 20 to 30º). This makes J5 to not reach 0º.
Another solution (if trajectory has not to be totally straight) is to put WJNT motion modifier at the end of the movement instruction, but be careful with that. Gripper normally does strange movements.