I use all modes.
First I have 3 joysticks. As they break I still use them.
What really helps, is the Avaitor joystick, but you could use anything you want. I think F5-F8 would work easily as I dont use them in game.
The first thing you want to do though, is map out your Mode1. This I use for pure fighter mode. This sets up flaps, wep, primary fire, secondary fire, and all guns fire. THe key here though, is you want to make sure you define your modes somewhere, then copy them to the other modes.
So Mode 2 now now becomes my dive bombing. Which basically changes the fire primary to changes to weapon select, and some other small details, that use. Then after weapon realease I immediatly go back to mode 1, with the flick of a toggle.
Mode 3 now becomes my bombing mode. Alot of key differences here. What ever works for you.
Mode 4 is my GV, and thats got some major key differences there too.
Modes, Gotta love em.