seems to me like you are the rong fit in this guild not they - they are clearly super casual and you want more - either accpet their rules or find a new guild -I'm a raid leader in a social guild on an RP realm, and we've mostly done mythic+ until recently. I want to get into heroic and mythic NH, and a few people seem to also want more progression. However, we have a huge problem with under performance. Instead of profession this week, we regressed and couldn't even get heroic Trilliax or normal Gul'Dan down this week when we'd killed both on previous weeks.
I've tried to be Mr. Mean and required 350k dps for heroic, along with saying people who die to fire get benched. It's hard to enforce those things though when it's co-GMs who are screwing up. And I get called an elitist and a terrible person for wasting people's time when they get kicked from raids.
I study my class and pull dps in 90th percentile and it shows me at 95-97 for my bracket. (this is normal mode as we haven't gotten anything past Trilliax on heroic). There are a rogue and warlock who also parse high. We still die to enrage timers or get super clutch kills. If I kick low dps, I get called out and the GM invites them back for another go so they don't gquit. She's a lot more forgiving than I...
I just don't know how to get people in shape for heroic progression. I learned my class by watching a bunch of guides. If I link guides to people, they just say their dps is low because they don't have Legendary XYZ. And some people pull very high in mythic plus and bad damage in raids.