Hi, and welcome to the forum!
You've got a great car there and I'm sure you will get fantastic enjoyment from it.
I have the standard 981 with PDK but the functions are the same.
As regards the parking brake- what you are seeing is correct. When activated, the red (i) light comes on.
The orange (p) light operates if you try and pull away and auto disengage isn't operable, or if you need to activate emergency braking by pressing and holding the parking brake button while on the move.
I find the Start/Stop very annoying as well. It's operation is designed to defeat its intention - that, as soon as you release the foot brake, the engine restarts. So, considerate drivers who set the parking brake after a time to avoid dazzling those behind succeed in the engine restarting needlessly. One can see that they do this to prevent a pause when pulling away but it is annoying nonetheless.
I presume you have seen the switch on the console below the manual spoiler switch which defeats the Start/Stop? Unfortunately it also defeats the coast function in PDK cars. Also, setting Sport mode defeats Start/Stop.
These button settings do not persist after an engine restart, but if it is a big issue for you, an American company called T Design offer a small, easy to fit module that remembers settings and preserves them.
Details here
https://t-design9.com/memory_module.html
I don't have one, but do have their phone holder which works well.
Have fun!
Neil