As to mythic acid, you need 20 people on the server to do mythic raids. I think most of your playerbase voted against it.
I don't know if the answer would be the same if we asked that question today. That said, we can field 20 people (on Fridays, anyway), but our dps as a whole is not up to par for mythic raiding. We'd also have to start sitting people if they didn't fit the mold of what we need, and this would probably happen regularly, e.g., we are very melee heavy most of the time.
Add to that the fact that a lot of people in the guild don't do some raid prep -- they show up on Fridays and sometimes Mondays, but some aren't flasked, some have no (appropriate) food, etc. A lot of people aren't pushing M+ for better gear. All of this makes for a difficult time raiding anything mythic (including H Helya, because she's definitely no EN H). We are still having trouble with H Guarm, and he's a loot pinata by comparison. This isn't a hardcore guild and we're well aware.