Good way to test functionality/compatibilitiy of your bar mod w.r.t pet bars (afaik Trinity also displays a pet bar seperately instead of replacing the main one) would be the Chess event in Karazhan, or the Shartuul event.

What I did was to not rely on the pet bar, but to bind macros for the various abilities, and put them on action bar #2.

I could then keybind them to more natural things than control-# for when I get ghosted. This worked very, very well for me.

Hey, I was just wondering if the /cast Spirit Lance/Volley/Chains macro's still work? Heard some rumours about them not working anymore, so before I'm wiping my raid tonight feel free to answer .

As a general rule, if you're using a barmod you will get a 'normal' pet bar in these sort of events, whereas folks with the stock Blizzard actionbar will have their main bar change over to a special 'possession' bar (which may screw folks over by rolling their own macros off of the main bar if they aren't expecting it). There isn't a good way for barmods to automatically roll the bar over since there is currently no state driver for that sort of event. See posts 68 - 74 here for more details on that.

Yes, the macros still work.

As an additional trick for folks who don't play a class that has a pet ever (rogues, druids, warriors, non-frost mages, etc), you can macro slots 1-10 on your primary bar. This thread mentions the details, which is to basically set up macros along the lines of:

And so forth, all the way through PetActionButton10. This causes your primary bar to function as the pet bar in situations where you have a pet, without having to rebind anything. Just make sure that if you're doing it this way that you don't have the macros on a bar that might be stance-shifted off at a bad time (i.e. warriors and druids).

If you try using macros like that as a class that has a pet some of the time, it will be sadly useless to you - Warlocks, Hunters, Priests (Shadowfiend), Mages (Water Elemental) will have their actions locked to the pet bar while their pet is active with that sort of macro.

Yes, they all need to be individually bound, or at least you can't just put them all on 1 button, unless it's changed since I tried and failed at that XD.

I like:

/cast Spirit Lance
/targetenemy

which just tabs for you (in this sequence it also allows you to manually target a construct if you want to do that).

I personally use a bar mod and just slightly extended my normal macros specifically for Teron, for example my consecration button is:

Something like this should work perfectly for all non-pet classes.