Looking for advise for turning basement into home theater area.

Hello everyone!
Please take a look at my finished basement (imgur link below - has 1 video plus 3 pics) where I am planning to set up a dedicated home theater section. I have not finalized any of the equipment yet (apart from the fact that I want a 4K projector) because I am not sure what will best fit the room that I have.
The layout of the room
Length - 20’ 9”
Width – 15’
Height - 8’ 8” (where ducts are not present) & 7’ 6” where ducts are present
Here are my questions –

• I plan to project on the 15-foot wall onto a screen that will be mounted in front of the door. The door opens to the unfinished area where electricals and a sump pump are located. Folks will be sitting near the half wall about 20 feet away. Is this a good idea?
• I would like to have a 140-inch screen so based on the calculations I saw online the height of the screen needs to be 69 inches. With the wall being 90 inches high is this doable.
• I plan to mount the projector and the joists run parallel to the 15 feet wall. The joists have a predrilled hole (~ 9 inches in dia) from where plumbing and electrical wires are already passing (See last pic). My plan is to push smurf tubing from behind the 15 feet wall to where the projector will be mounted (~13 feet away) to run the HDMI plus power. Is this doable and does it violate any codes?
• If the above is doable then is it okay to run power and HDMI in one smurf tubing or do I need to run two different tubes? Alternatively, do I need an HDMI extender?
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• If there are any questions, please let me know. Based on the responses I will ask follow-up questions. Thanks in advance for your valuable suggestions.