If it took flight then it landed.
Landing means bringing something to land. Nothing figurative about that.
"Literally" is such a misued word where most of the time, it doesn't even make sense.
Did you get the katana idea from my post a few years ago?
https://www.nissanzclub.com/forum/threads/whos-going-to-modify-the-katana.430/page-4#post-17746
No need. Especially on stock height.
I upgraded my endlinks when I got new sway bars. They started making noise soon after so I threw the stock endlinks back on.
Several track events later and oem is still holding up fine.
Feel the car on the track first.
What's good on the track can make a horrible street car and possibly dangerous.
To answer your question, it depends if you will lower your car or not. If you lower it, you will need adjustable suspension arms to get the car back into alignment. Also, the soft...
I would upgrade the sway bars first. They help with body roll more than coilovers/spring & shocks.
When you start getting into coilovers, you need to consider getting the car back into alignment if you are changing ride height. That requires new suspension arms.
Never a bad idea for fresh...
Definitely swap to dot4. No need to go back to dot3 afterwards. Everything else in the car will be fine based on your experience level.
Bring an air compressor to air up if you will be messing with tire psi. Check your psi as soon as you get off the track and adjust from there if needed...