Okay, the first thing that doesn't work is that you haven't run flexible conduit of at least 1.25" diameter from the equipment closet to the TV location.
Second thing is that you intend to stick hot electronics into a closet. This isn't terrible if you give them plenty of room to breathe, but overheating is the number one killer of electronics.
You SHOULD run wiring for a subwoofer, because it's cheap and easy. If you ever sold the space and someone who wants a subwoofer were to come in, why would you screw them over by NOT including that cable? Pick a location that is out of the way. Either in a corner or behind a couch or similar.
Infrared repeater systems will use up a cat-5 cable. I would run at least TWO more cat-5 cables (total of 4) to the TV location. They are super useful for a variety of things. Make sure that you also have a NETWORK cable run behind the TV location and to the equipment closet location.
But, yes, there are plenty of infrared repeaters on the market which allow you to use a standard remote, or a IR universal remote to run the equipment tucked away inside of a closet. Some better universal remotes also will use RF, and that gets converted to IR inside the closet to control the gear.
It is hard to know if your speaker placement is solid without knowing where your couch is going. I assume that it is in line with the front pair of ceiling speakers.
Finally, I must say, it bugs me that your front three speakers are jammed together like that. You will get almost ZERO stereo imaging from such a setup.
I will say that both my wife and I wear headphones for almost all of our normal TV viewing, we have found, over the years, that it provides a very good way to personalize our audio for the way we like to listen to it. Just something to consider as well, but that can be added later.
Here is a video about setting up a IR repeater, there are a ton of videos about it on YouTube...
Here is a pretty standard IR repeater kit:
NOTE: You can extend the IR receiver target by using cat-5 cable in between. You can also use a different IR receiver target which connects to the phoenix block.