grrr, When I tried to post it, my longer post was deleted by the gods of internet problems. Excuse the brevity of this repeat.
1) It is hard to tell much from your photos. Try "macro mode" on your camera, it should take better closeup photos. Those photos are rather blurry.
Edit: Your photos aren't actually that bad. It was a bad first impression on my part. The glare isn't great though.
2) You might find http://www.endless-sphere.com/w/index.p ... leshooting
helpful. It's method's rightup on fet troubleshooting.
3) Solving your fet problems does not gaurentee that something else didn't also blow/melt on your pcb. I'd go for careful inspection and in the future beefing up your traces [One easy way, especially with boards that are a few copper wires and excessive solder globbed, is to use copper braid on the traces. Carefully check for shorts around the fet legs after you beef up the traces. This should only be done after you fixed the rest of the borad]
New to endless-sphere? Notice a lot of signatures recommending Ebike.ca? That's because it's the best place for a quality and manageable, (but still 'real'), first build. Justin is a solid supporter of electric bike development, and a good source of equipment.
My hat off a thousand times to the green people that effectively run this forum. The ES Mods are superb.