You are only limiting yourself by shooting minor... Minor has a different scoring system so you get less points for C's and D's. By shooting 40cal you limit the number of rounds you can carry. Like 17 vs 21 and 24 vs 29 in your big stick. 9 minor might not run an open gun very well either, the compensator is there to divert gas upwards and shooting minor you will have less gas and a slower slide cycle. That is why 99% of open shooter use 38 super/super comp or 9 major...
I use a 9lb in mine because I always worry about not stripping off the first round off of a reload or tight bullets, so you can go with a 7lb but thats why I use a 9lb.
6 and 8 dots are what I prefer... That allows you to have a large enough dot to see against different backgrounds as well as sun and not to big to cover up targets for percision shots...
Practice and form are clearly paying off... Also when the RO says that part about "load and make ready" that's part of the MAKE READY, haha... Nice shooting...
I think to practic weak hand is important but not the most important... Remember its only about 1% of USPSA. I've shot 2-3 matches a month for the last 2 years and 5 Level II matches and only used weak hand maybe 10 times... Its important to know and practice but not your total focus, in my opinion...
I haven't had enought experience too use all the powders mentioned but, I didn't care for the HS-6. That dirtied up my gun so quick. I then tried tight group and it was not right either. For the last 2 years I've used N350 and I'm very happy with its preformance and it's pretty reasonable to make major.
At a local level 1, I don't think anyone would ever question it. Moving up to level 2 and 3 you shouldn't be doing it (in production at least). Even though they might not know but its an honest sport and it shooters responsibility.
Definately do more walk throughs and even dry runs (holstered of course). Get it so you can close your eyes and envision it. Slow and smooth. Find a Master class shooter, this is a friendly sport, and ask him to walk through with you...
It might depend on if you are shooting major or minor... I shoot major and I like the 124. It feels right when shooting and I don't feel like it slows anything down or wastes powder...
Thats how all great Marine stories start... So there I was, NO $HIT, knee deep in bodies, one bullet left, knife in my hand... and it keeps on going...
Go ugly early and avoid the 2am rush (Partying with British Royal Marines)
Just stay down and let them waste their ammo, then well just walk up and shoot them! (USMC Scout Sniper Iraq)
We don't send troops inside buildings after terrorists, we knock it to the ground and burn it! (Israeli Defense Force)
Speed is a part of your score so its important, but a good rehearsed plan is even better... Pracitce your plan, being a new shooter find someone to help you, this is the most friendly sport ever, then work your plan as fast as YOU can... Good luck, keep shooting...