Staying on the lower level tends to be easier to avoid damage (It uses its annoying moves less frequently)
Try to avoid melee range because it will trigger a melee attack that does massive damage and knocks you down (So you are stunned and can't do anything. Not even healing using Bloodpump)
For the Rocket Barrage, keep moving and avoid cover (As the rockets can destroy it)
For the Gun Barrage, stay in cover.
When Poison Gas is used, go to the upper floor.
You can jump over the laser beam instead of taking cover, allowing you a free chance to deal damage to it (Especially the weakpoints on its back)
EMP damage is great. EMP grenades, weapons like Fenrir, Genjiroh and Yinglong and System Shock quickhack are useful.
Muscle Memory perk from Reflexes is very useful to allow you to reload while sprinting.
Smart weapons are useful for targeting the weakpoints on the Chimera. Though in the second phase it will prioritize the Chimera weakpoints over the drones.
When the 2nd phase starts, take out the attack drones ASAP. Then take out the repair drones. The Attack Drones can be pretty deadly on Very Hard.