After working in silver I always have to remind myself that switching from silver to gold is different in that gold can be spot soldered. The tiny flame I use can be concentrated on the seam of the bezel and solder.
The gold bezel does not need to be an even temp like silver does to get the solder to flow.
My thoughts on:
when I solder the bezel to the metal base/bottom... Sometimes solder will move with the heat or when heated quickly. If so, I would heat the flux to set the solder in place. Paste solder can be helpful.
If soldering a gold bezel onto a silver base:
I would heat from the bottom up = heating the silver base evenly
flash flame the top of the silver base inside of the bezel where the solder is if you feel heat is needed there.
Keep moving your flame back and forth with most of the heat coming from the bottom. When your silver evenly heated and at flow temp it will flows.
Gold will sink into silver so as soon as your solder flows remove the flame.
I agree 14K bezels are hard. A higher carat will help. Also, check your adjustment on the hammer handpiece to soften or harden the blow.
That's some of what I experienced, hope it helps you or someone else.