1) Power Auras and Weak Auras both have the option to have Icons instead of textures, in Power Auras I can't exactly remember what it said but it's a check box right next to the size slider. In Weak Auras you just make an "Icon" aura.
2) I have no idea how to make complex macros but the macro thread might help.
3)
JSHB4 worked for me for my alt, it's pretty neat because it kind of tells you where you next Cobra Shot will take you in terms of focus, so you know if you can cast AS or KC right after that shot, etc.
4) Well... you CAN macro in pet abilities to your abilities but they will be used whenever you use your ability. It seems like you want a macro that can magically just KNOW when you need them, and I think that's impossible? What I do is just macro my pet abilities to F2-4 because they're not that hard to reach and the pet abilities that you can actively use are not that many. I thought heart of the phoenix was passive? Haven't played my hunter in a long time.