ArtMetal

Actaully, AC would be problematic with bronze welding. You'd be begging for problems when the current reversed and both cooked the tungsten and tried to plate it with outgassing elements from the bronze. Cleaning is only required with aluminum, not bronze. Stick with DC.

High frequency start is always handy with TIG, but for silicon bronze it is not needed while running. Some other bronzes it might be handy, but I can't personally say from experience.

TIG works fine as a heat source for brazing almost any metal. After all, it is fundamentally nothing more than a heat source developed from an arc as opposed to a flame, and has the added benefit of a shielding gas to inhibit oxidation, a function performed by the excess carbon in acetylene.