this thread started as a lot more generic question about a boxing Asian MA comparison and evolved in a Boxing Vs Thai thing.
I won't stray from this as it seems to be the focal point of the discussion.
Personally I've trained as a kickboxer (fighting with low kicks rules for ~2yrs) with enough fighting experience in regionals and such (no knees/elbows, no clinch experience other than sporadically in training bouts only) but I believe I have a good grasp of the muai thai concepts be it from a trained spectator aspect.
Also I've boxed regularly for about 3 yrs. (I weigh in at 69kg 6ft just in case you need to setme up for a friendly bout, I hope not all arguments in this forum come to that

??)
to the point:
there is such a thing as an inverse simplicity/proficiency ratio...
meaning that the average to good boxer is in far better command of his tecniques than the average to good muai thai fighter. I will not consider exceptional fighters from either discipline.
the comparison is in my opinion a little biased against boxing because it doesn't take into account the many things thai has borrowed from boxing tecnique. Who doesn't remember some years back, thai boxers with a ridiculus upper body fighting stance (hands open on either side of the head, too extended by far) lending no passive defenses to the head.
Compare this with the "traditional" boxing stances adopted by most modern (as in last decade) thai fighters.
So boxing is an essential part of everyday training for the thai boxer.
boxing training on the other hand involves no kicking whatsoever!
So the question is really: what rules??
a boxer getting into a fight with thai rules without having had some sort of coaching will have no luck at all. He will not even be able to recognize attacks originating below the waist as a threat source. Even though boxers have very trained legs, conditioning is a whole different proposition. Even a medium impact low kick will leave a boxer limping, and deny him the mobility he needs to avoid ensuing attacks. So he would have to be both wary of the legs and lucky to close the distance without getting hit with a damaging kick, and then stay inside and do some damage of his own with his superior boxing skills.
Now if a thai fighter was to get into a boxing contest with a good boxer or fight with boxing rules I'd give the boxer a 80/20 chance of winning at this time. (the balance will change over time but mainly because of the thai fighters incorporating more and more western boxing tecniques in their training)
Now guys don't go telling me that the comparison should be made on the more complete art's terms or some such. (because the thread more and more resembles one with a subject of "can boxers make it in muai thai?"). Both sports are artificial forms of confrontation with an arbitrary set of rules (I mean why not biting eye-gouging, joint dislocations and such).
to wrap it up, it would be a lot more productive to focus on what thai fighter would have to do to further improve his boxing skills?
what should a boxer do to expand his fighting arsenal, or to become good in muai thai (if he cares to make that transition, he already has made very good progress in the part of muai thai that involves boxing)
Bye for now