I can relate the these problems. I would like to be able to hit Summon III on mt smn and it change the 3 pet abitiles.

But, I was able to come up with a work round with a macro like this..

/ac "Contagion" <t>
/ac "Landslide" <t>
/ac "Flaming Crush" <t>

This way I have 1 macro with all level 40 pet abilties on. I have done the smae for the level 20 and and starting pet abiltiles.
The only issue I have with this setup is the lack of /micon command working with pet abitiles. So I just have to have a hot bar loaded with the pet abilties so I can see recasts for these abitlies.