Layout help, I'm going deaf in here!!!

Preliminary info: I am a structural engineering student in Philadelphia PA USA; my band was given this space to practice in. We like to do our own tracking and I have been reading how to mix, so eventually I would like to use the room as a combination live/CR, currently it is for live use only because my DAW died. We play progressive / melodic metal. I use Cubase with a Behringer control surface, and Delta 1010 interface. Sound leakage isn’t really a factor since it’s a commercial district building and we usually track off business hours. We tend to perform at moderate levels to hear over the drums. In this room our current layout may be detrimental to our hearing because there is a prevalent flutter echo and some room modes around the 12th fret E on the bass guitar. I have read the home studio book by Rod Gervais and was wondering what alternatives I have for identifying room characteristics. Is there any way to rent the equipment needed to test the room? Since I'm only tuning the room for a short period of time this would be great. The ceiling height is 10'-6" and has steel beams at 8ft so I intend to put some 2x3 studs up there, staple cloth to them and lay sound absorber up there to muffle things, if recommended. Currently the ceiling is some sort of concrete board. EDIT: The floor is 6-8" cast in place concrete. The room is on the 2nd floor of an office, below is garage space so noise pollution in there isn't a concern. We currently have some commercial carpet on the floors. Attached is a PDF and some images of a Revit drawing I made of the situation. Please let me know if you require any more information to assist me. Thank you in advance. MAIN GOAL OF POST: To identify the best orientation of the mixing desk, amplifiers and drum set for tracking. To identify remedies for room modes and flutter echo. Problems with existing setup: Amps are firing into the long wall which makes them inaudible unless you're directly in front. Bad for performers, causes ear ring. Do all four corners need to have superchunks? Currently we have 3" 8lb rockwool installed diagonally in the corners with no gap at the edges to the wall. Floor to ceiling height. Behind the panel is air space. The keyboard player wants to be as far away from the drums as possible. Of course the two instruments with the most cable runs to the mixer want to be the furthest apart. Approach to alternative designs: Rotate the CR 90 degrees to the live room. This would give me the opportunity to treat the walls for the mixing desk without the monitors firing into the bass absorbers in the corners for the live room. I would think that the mixing desk is better facing the long wall. Place the bass and guitar stacks so they fire long ways in the room. Size of the drum riser is manageable, maximum size is 8' x 8'. I don’t use the analog deck while mixing, just tracking preamps and live mixing.