|I agree with #1 & #2 both.|
For gaming the 2500K would be more than enough.
For gaming a 2TB drive is excessive (unless you have other needs)
Not sure how much speed you would pick up with an SSD drive, but that at least there may be a reason for.
You should have chosen a graphics card and quality memory just after choosing a MB & CPU, they are THAT important to gaming.
I cannot understand what a gaming keyboard could give you that a $20. keyboard and a quality mouse can for gaming.
You do not need a water cooling system for gaming. While you will probably be overclocking, extreme overclocking will not give you the stability you need for gaming and a decent air cooled system can handle that more reliably. Plus you will get better overall air flow over all of your components with an air only system.
A fancy case is not always the best case, quality and good air flow design is more important.
If money is not an obstacle then get the 2600K and the SSD, if you like, but everything must make sense and just buying the most expensive is not always the best.
I do not know the motherboard well but I have done well with Gigabyte and Asus is usually spoke of well.
You have to be a little bit crazy to keep you from going insane.