Expand the View Node. Right click and choose "New" to create a new view rep. Name it whatever you want or leave it "View1". Now turn the visibility of the sketches off and they will stay now.
With the "Master" view rep selected, it is locked and can't be changed, so the changes that you make to the "Object Visibility" are lost when you close the file. If you turned off each sketch by selecting it and unchecking the visibility, it should stay on/off even with the Master view representation.
I think you are going about this the wrong way and doing too much work.
Sketch1 is unconstrained.
Sketch2 is not needed.
Right click on Sketch3 and then hit F8.
Sketch3 is not constrained and already has way too many constraints and dimensions.
You should not need to repeat dimensions - pattern features rather than sketches.
...I gave up after that. Most of your sketches are not needed and it appears that you should take some time out to go through the tutorials.
What book are you using to learn Inventor?
Have you taken a class?
I learn Inventor without books. I'm Ukrainian. The Ukraine use method "tourns and mistakes".
I recommend that you spend a couple of weeks going back through the questions posted here finding as many posted files as you can and examine the problem and solutions by editing the sketches and features.
Have you gone through this
Inventor is a professional program and deserves (requires?) a professional level of preparation.