A lot of overpriced components in your list.

I would go with something like this https://pcpartpicker.com/list/yfFzwY

Drop down to the 7800x3d, its only like 8% slower and costs $100 less.

Super overpriced motherboard.

Ram is good

ssd is good

For the gpu the 9070 xt is a really good choice. I would maybe consider the RX 9070 non XT though, its $150 cheaper and is only 7-9% slower on average in 1440p, so much better value. Still has all of the same features as the 9070 XT. if you would rather go with the XT it's fine though.

Went for a different case, the one you chose is fine, I personally like the Lian Li one better.

INSANELY overpriced PSU, the one I picked is really reliable and well built.

I would STRONGLY suggest splurging on a 1440p high refresh rate QD-OLED monitor like the one I put in the list. your monitor is just as important as any component in your build.

for some of you questions:

You should definitely be able to get around 5 years out of this system.

An airflow configuration like you described will work alright.

the pre-installed GPU fans are more than sufficient, don't touch them.

For dust, most cases now a days come with dust filters that are pretty easy to clean.

Let me know if you have any other questions!