I don't see a way to recast a pet during battle with my sk/necro/mage... is this possible?

The first tier pet talent for necro can be maxed out to instant cast a pet when you cast your free DD. But that's it. Generally pets are not a useful contributor to DPS, but the meat shield aspect can be mildly useful.

I may have miscommunicated my question. How do you cast a pet in battle? I see how to cast a pet pre-battle, but can't figure out how to drag that icon to my in-battle bar.

You can't.

This might be changed at some point, but when I initially designed these skills, I made a non-combat panel and a combat panel. It's a shit design, but that's how I did it way back when I barely knew what I was doing. This might get totally changed in the end. There's really no reason to have two different panels.

Couldn't you just duplicate the non-combat pet summon to the combat panel?

I am very clueless about all things programming.

Ya, it would be easy, but it would just take time I don't have right now Finishing talents is more important.