How can you pipe hot melted candy into free-form shapes?

You might try welding gloves or fireplace gloves. (fireplace gloves tend to be longer, and might go up to your elbow).

They're typically made of suede, with an insulated lining. I use them instead of pot holders, but they also come in handy when I'm doing large amounts of grilling (once a year, for our departmental picnic, cooking for a couple hundred people).

The fireplace gloves also come in handy when camping, as you can reach in to move logs if you're quick about it. The only issue is that too long of exposure to hot, dry heat will cause them to harden up and lose their insulating properties. I have to get a new pair every few years or so because of the way I use them.

I also have some really heavy duty rubber gloves that I got more as a joke -- I'm not sure if they're for haz-mat purposes, or what, but they come in handy for when I have to deal with hot but wet things. I've also used them when dealing with cleaning out the fridge at work that had gotten pretty scary (it was near a conference room, and people using the conference room would leave stuff in there and forget about it). I've seen similar gloves, maybe not quite as thick, though, at a restaurant supply store near heavy rubber aprons for the people doing the washing up.

And, if those still don't fit your preferences, you can find silicone potholders ... they've got good grip, and you should be able to roll it into a cone around your piping bag.

You can try using heat resistant gloves meant for grilling.

I imagine you could dip a metal or wooden stick into the hot mixture and create shapes as it drips or flows off the utensil while moving the hand (since you are attempting freeform shapes). With a bit of experimentation it may produce some interesting results! :) However I have not personally worked with melted candy, and am looking forward to hearing how you achieve the results you desire.

If you are using candy melt wafers, I've had good results from simply allowing the melted wafers to cool a few minutes after pouring them into a bag to pipe. Just pinch the tip of the bag or somehow fold it over so your wafers don't leak everywhere and lay it in a small bowl until it's cool enough to hold or hold in a towel but still fluid. If the wafers solidify before you're ready, or are gunked in the tip of the bag, you can gently remelt the wafers in warm water.