Hand2Note automatically recognize every player as fish or reg and assign corresponding color mark to the player. (It just takes the first fish color mark starting from the top of the list if player is a fish and the same for regs)
It's not possible to customize main window and there is no other section in players list in the program. You can open popups on players by double-click on their nicknames and compare the stat values manually one-by-one. You can also use Range Research tool to explore pool tendencies.
Please note that if your HUD consists of several panels with different display conditions, then you need to place all these panels(as they appear) in the correct places by mouse. Only after that, they will appear where it is necessary.