This is what I would personally would like them to do with stage hazards.
General
Hazards do not do damage though armor, so you can completely negate a thrown object with a MBDC.
Increase the amount of meter needed to MB a hazard, up to two bars.
Thrown objects no longer track, instead you have to aim them with inputs.
D+S throw the object directly under you.
U+S throw the object straight through the air forward.
F+S throw the object diagonally far.
B+S throw the object diagonally close.
MB+S gives the normal armor and the object tracks again.
Gadget characters can now MB the explosive dodge to give them armor.
The divekick Flash, KF, and Raven have is now an overhead and causes a ground bounce on hit, allowing for a followup, scales like a D2.
You can now MB the divekick to give it armor.
Specific hazards.
The plant in Arkham can now be used both ways by both types of characters.
Can now plant explosives or divekick of chandeliers if you so desire.
Robots on watchtower have increased spawn time, about 3 times as much.
Adjust the hitbox on the gadget water pipe on Atlantis, the opposite of Sinestro's fear pellets, farther away, you can duck it.
The robots on Rooftop now can not be thrown by power characters, instead they are used the same way as gadget characters. They also no longer respawn, but all 3 of them are on the map from the start, bullet one is in the center, fire on the left, plasma on the right.
After a hit from one of them, you can now follow up with a combo, however it is scaled similar to a D2.
If a gadget characters use it with a D input, it plants a bomb on it to destroy it, if a power character uses a D input, they throw it directly downward, destroying it.
The masks on arkham can now be blocked.
Pig stays the same.
Reduce hitboxs across the board.