Advice on key rebinding

I just got my first ever gaming mouse ( a Razer Deathadder ) to replace my ailing ancient trusty 3 button mouse.

I’ve changed the grenade and melee bindings to be the 2 thumb buttons and that seems to work ok ( haven’t tested the melee properly yet ).

What keyboard and mouse bindings do you guys change? Melee Krieg with “V” is pretty tough.

Also is there any point in installing the software? I can’t imagine needing to.