When my group first started doing divebombs, we made the mistake of not realizing that you REALLY need to be right up against the wall for divebombs to trigger properly. Basically, you want to be so close to the killwall that Twintania faces toward the OUTSIDE of the arena when she comes down to divebomb. If the target for divebomb is too far away from the killwall, she will face inward from the outside and hit most people (you can see which direction she is facing if you are zoomed far out enough). Be careful not to actually get yourself killed by the wall, though! I like to back in slowly to the wall so that I am as close as possible. When dodging divebombs, if everyone is in the right position, you don't have to run very far... just to the top of the hill and back again.
Another little tip: when you are doing the first set of divebombs, you will probably hear AND see the icon. You should move as soon as that happens. When you are dodging the second set of divebombs, you might not hear it (because of all the noise going on while the snakes are being killed), so you REALLY need to watch for the icon. After a while, you will get used to the timing.
Anyway, no one should leave negative comments for you. You are asking honest questions and plenty of groups have struggled with divebombs.

I do not think you should be having issues due to people being on PS4... my first group beat it with several PS3 players, in fact. As long as none of you are lagging, you will be ok.