Need advice on improving the Audio in my Home Theater

Hi, I am a novice in the world of home theater, but recently setup my home theater with a 5.2.2. System. I have Martin Logan’s XT- F100 for front channels, XT-C100 for center channel, XT-B100 for surround, MC6HT for Atmos and i have paired these with Martin Logan Dynamo 1100x and an older SVS PB12NSD sub. This is being driven by Marantz cinema 60. I am in a dedicated room with no windows and a weird room shape. See pictures where one wall is sticking out due to fireplace on the other side of the wall. It is a small room 11.5ft. wide, 13 ft length and 10ft. tall ceilings.

I have a JVC NZ800 projector and a 133 inch screen which I am happy with but think the audio could be better. I am ~$35K in this room and would like to be careful now. To improve audio, I am thinking of 3 steps-

Step 1- Get the room treated (Vicoustic, GIK)

Step 2- Get an external amplifier (Anthem MCA 325 Gen 2 or Parasound A31) to power LCR

Step 3- In future get side surrounds and upgrade to a better receiver (Marantz Cinema 30, Denon X6800h)

I need advise if I am thinking this in the right order or if you would suggest something else given the shape of my room. Do you think I made a mistake in buying the speakers. Anything else I should think of before spending any more money on this room

appreciate the help