I personally see no need for ECC ram. It is wholly unnecessary for any consumer, and will slow down your system by a percent or two.
I also disagree that you need a 700w PSU. I’d save some $$$ and get a 500w. Your system, as currently configured, will not come close to even 500w.
Your mobo is also extremely pricey, and I’m curious what benefit this is getting you that you want.
I would personally get 2x 1TB SSDs and RAID 0 them, but that will lower your reliability some. Still, SSDs are extremely reliable, so it’s unlikely you would have issues. You could also always get a 2TB NAS quality HDD and run weekly backups to it to maintain reliability, or if you have gigabit internet, you could probably just do differential or incremental cloud backups.
As to your case, given your habits of smoking, etc., I would definitely not get a test bench case. I would also strongly recommend against a fanless case with a performance GPU. You can get “silent” cases that are in the 20-30dB range, which would be extremely quiet. You can also get filters for some of them so you aren’t getting smoke in your system.
You will probably want to get an aftermarket silent fan and replace your GPU fan with it if that is something you are comfortable with if the most quiet system possible is your goal.