just monitor how well you son chews, i agree to start off with soft and go from there, a friends baby had no teeth yet and was eating like a pro, my daughter had most of her teeth really early and wasnt such a good chewer(really monitored food size, ect)... it all depends on the kid and how well they eat.. every child is different... but yes they can gum up food with out teeth
I was feeding my son all the things you have mentioned and he only had two teeth. Their first teeth are all the ones in front, so really...they aren't their chewing teeth anyway. They can gum things no problem. I just make sure things are quite soft and/or small. Start out with very soft things, like pieces of banana or something if you want.
I give my son pretty much anything now.
I was feeding my daughter steak and she only had 2 teeth. (She might not have even had that many, I honestly can't remember) We also didn't use baby foods though. I went with baby lead weaning and she went straight to table solids.