Just a quick couple of thoughts.
You want some level of separation between electrical wires and network/audio/video cabling. You run the risk of interference if you put them too close.
That would have to be one pretty big power cable.
I don't know what would happen if you put your network terminations right next to all of the electrical going in/out of the breaker box.
Nothing.
I know several people who have their home routers wired with all incoming and outgoing connections at the electrical junction box.
Reduce what you put into the conduit by taking things like the 12ga speaker wire and not putting it in the conduit. Speaker wire should be fairly safe if protected by a decent height off of the floor and placed far enough back to prevent a nail/screw from hitting it (or use stud cable protector plates). That should open up some space inside the conduit.
There was consideration to put speaker wire in a conduit???
It is just speaker wire. By the time that wire type may change, we'll all be long dead.
The only thing speaker wire needs to be for construction is rated for in-wall use (CL2 if i recall).
Keep in mind that the conduit also needs very gentle curves in order to get any future cabling through it and a lot more space than you think you may need.
45 degree elbows are fine. The 90 degree elbows are problematic.
