aozger, I'm glad the day ended without anybody getting hurt. And in general, I think you've taken the criticisms pretty darned well. But this opinion, you need to change:
As far as the charter and the DM, since my previous ocean dive was a completely different and fun experience, my original thought still stands that one should expect more from them, otherwise it makes the difference between a DM and a Rescue Diver (or a Master Diver for that matter) obsolete.
I just finished taking the written exams for my DM class, and one of the specific questions had to do with the role of the DM in dive planning. It is the DMs role to give a general overview of the site and the proposed dive, including maximum depth, dive time, and conditions to be expected. But it is quite specifically stated that it is NOT the DM's role to do dive planning for individual divers or buddy teams. It is YOUR responsibility to look at your experience, your competencies, the gas you are diving, and your teammates and come up with a dive plan that works for YOU. And it is your responsibility to execute that dive plan safely. The DM is there for insurance -- would you plan a driving trip where you EXPECTED to have to use your auto insurance?
You did learn one really important lesson from that dive, which is that anything that is not right at the inception of the dive is unlikely to get better by going further underwater. However, I'm not going to fault you as much as some writers have, that you didn't go back for more weight. I have experienced the pressure that charter operators can put on divers, to get them in the water FAST. It takes a fair amount of backbone to resist this. And the culprits may be DMs or even instructors. My husband had to go nose to nose with an instructor on a dive boat in the South Pacific last fall, when he began to deride us for doing BUDDY CHECKS. This is someone who is supposed to teach people to do this, making fun of the only buddy pair on the boat who were doing it.
Don't let the bad example of the others on your charter boat suggest to you that it's okay to stop going over a dive plan, or doing equipment checks before getting in the water. It's not. The couple of minutes you spend doing that will prevent you from entering the water with malfunctioning equipment, or your gas turned off; and NEVER should any team get in the water without being familiar with how they are going to share air, if it's necessary, and where one another's weights are and how they are released. These were good habits you were taught. Be a PITA on the boat and to your instabuddy, and insist on doing your checks.