There are currently about 4 million registered commercial fishing vessels. According to one study, 80% of americans went fishing in the last year. The current U.S. population stands at 310 million, making for 248 million people who took one fishing trip, or 62 times the number of commercial fishing vessels. You don't have to convince me that commercial fishing 'processing plants' are detrimental; you DO have to convince me that recreational fishers aren't. As for the trash fish, when I was fishing, the boats around me would kill any dogfish they brought up because they weren't "desired" and were stealing the fisherman's baits.
I don't think your numbers tell the complete story. OK, there are 310 million TOTAL population in the US. That's true. And if your number of 80% of Americans are fisherman, then the 248 million represents the total amount of recreational fisherman trying to catch fish. This equation in no way compares to the 4 MILLION commercial boats in the global fleet harvesting massive amounts of fish, with quite a large amount of their catch being killed and then just tossed back into the ocean, because it is not on their desired catch list. I guess we should not even talk about finning sharks, killing dolphins to harvest tuna, and related topics. Factor down the number of people who freshwater fish, since your equation takes into consideration ALL fisherman. Commercial fishing fleets are salt water based, and I believe we are really discussing what is happening in the worlds oceans. I do freshwater flyfish, with barbless hooks. And, I have never consumed a freshwater fish personally. It's all catch and release. All of my flyfishing buddies do the same thing. Many others do this also, to conserve a vital natural resource for others to enjoy for years to come.
This is simply false. If the top two fish in an area weigh 60 and 40 pounds when the largest dies, the 40 pounder might suddenly become the largest fish in the school by definition, but it doesn't magically grow to 60 pounds. There are some species where, in overcrowded situations, this will happen (ex. prawns in aquaculture) and maybe in sequential hermaphrodite/harem situations like with some wrasses, but even they don't get much bigger, they just change sex. However our oceans are not overcrowded and most species, especially gamefish species do not follow this fantasy.
Fantasy, no, I don't believe it. When you get the 'chance' to take one of the larger fish, the second in line does move up the chain. 40 pounds to 60 pounds is quite a large jump. I think your weight comparison is a bit of a stretch.
I do consume meat, but what this has to do with fish stocks except in the holistic "everything is connected" way, I am unsure. My consumption of fish is limited only to those species the research says are sustainably harvested.