So being rude to this DM is probably not the way to go. I read the emails, and I saw him as being defensive more than anything else. The encounter presented had only 2 problems:
- 9 PC's
- level+7 soldiers
Granted, both of those are firmly in the DM's hands to fix, but I have been a DM who prepared for 7 and got 11, I know it is tough to add to an encounter on the fly and not make it suck. Do we know what his *original* plan was?
This is not the first thread you have started discussing your DMing woes. Have you talked to him, frankly and honestly about it? Sure, an email with a list of grievances may seem like enough, but a face to face where he can understand that you are serious sound in order. If that is to awkward for you, I'm not sure you have a leg to stand on. Really, the goal is for you and he to both enjoy yourselves playing D&D. If that is not addressed, then you should enjoy yourselves *seperately*, but do please give him a chance to try it your way.
Jay