Let me begin by saying that, as a professional, paid, youth hockey coach, hearing stuff like this breaks my heart. THEY'RE. FREAKING. EIGHT. YEARS. OLD. No matter how seriously the coaches (and parents...honestly, the parents are generally every bit as bad as the coaches at this age) take it, this is NOT the NHL. And, what's more, nothing - NOTHING - that happens in any kid's 10U Minor season will either increase or decrease his chances of playing in college/getting drafted/playing in the NHL. Well...almost nothing. The one exception to this rule is, if the experience is SO negative for the player that s/he quits forever, I can GUARANTEE you that s/he'll never progress to a high level of hockey...
Anyway. Instead of focusing on skill development, it sounds like your kid's coach is going to waste the entire year trying to teach 'systems' to a group of kids that do not, I REPEAT - DO NOT - have the mental capacity to understand what it is they are learning. Studies have proven again and again that treating kids like they're miniature adults doesn't work. A child's brain does not process information in the same way the adult brain does. It just freaking DOESN'T. The kids may be able to learn the mechanics of the systems...but they won't learn the 'why'; and they certainly won't learn the strategies behind them. They won't be able to repeat what they learn and, in the end, they won't become better hockey players. Put differently, solely in the name of winning, this coach seems dead set on trying to create a group of little robots that have no creativity, no individual playmaking skills, and no hockey sense. And, for your kid anyway, no fun either.
(Thing is, though...I GUARANTEE that your kid isn't the only one not having fun...)
So. Enough about why this coach sucks...because let's face it, no matter how many utterly meaningless 10U state/national/global/universal championships he's won, if he's teaching systems at 10U and all he does is yell and curse, he does, in fact, suck. The question you have to wrestle with is, what do you do now?
I'd agree with the others that you probably need to get your kid off that team. It sounds like your house leagues are a bit of a joke (don't worry - ours are, too...) and it sounds like you have at least a cordial relationship with the B team's coach. I'd leverage that and see if you can't make a change. If not and the rosters are set, a year off from competitive hockey at 8 years old isn't going to hurt his long term development - just keep getting him on the ice in a positive environment where he leaves smiling and, most importantly, wants to come back the next time.
One caveat though - in any discussion you have with ANY person that's part of your club, I'd make sure that you keep the discussion about YOUR KID - NOT the coach. You don't want to get into a situation where you're saying things like, "that coach is a jerk" or "all that coach does is yell and curse" or "my son hates that coach". All of that may be TRUE, but getting labeled as the dad/kid/family that can't get along with coaches is NOT a good place to be this early - particularly if you're going to stick with this club long term. If you talk to anyone about this (current coach, club president, B team coach, other parents, ANYONE other than your immediate family), just say that it's become apparent that your son wasn't ready for that level yet and that you want to back off before he begins to hate hockey. If people give you a hard time about it, simply say, "I understand, but this is what's right for my son at this point. The last thing I want is to push this now and wind up with a 12 year old that hates coming to the rink!"
Never forget - this is a marathon, not a sprint. A million things have to 'go right' for any one kid to 'make it' with hockey...and, ultimately, the vast majority of those things are COMPLETELY out of our control as parents. As such, I believe it is our duty to make sure that we parents do the best we can with the things we CAN control...and this situation is one you can control. Get your kid back to a place where he has fun at the rink. Do it quickly. And do it without apologizing to anyone.
Good luck. And please report back. I definitely want to hear how your son is doing.