Materials that resist adhesion with molten glass even when hot I'm looking for ways to manipulate molten glass with (e.g. bending a heated glass tube). 

This article mentions that oxides tend to adhere, hence molten glass to heated stainless steel.

What materials could I use to manipulate hot glass? Perhaps I could coat the glass or instrument doing the manipulation with some sort of powder or liquid? 

The glass is soda lime glass which has a transition temperature of 550 degrees C, so the temperature it needs to cope with will be a fair bit above that.

Thanks
Professional glass blowers use graphite paddles to "push" the glass around.  But to bend a heated glass tube you need to know that glass is a very poor conductor of heat.  Thus it is possible to grasp the heated tube six or so inches from the heated spot and just bend the glass.  This works well for small bore tubing.  Just be careful putting the bent tube down.  Putting it on a high heat conductivity surface will result in the glass breaking.  In the old days asbestos pads were used, but that's a big no-no now.