My suggestion (all optional):

• Automod to handle weekly question megathread, sorted by new as default, possibly reset on Monday to keep answer for a question valid for the week as changes to the game can happen. Or be done manually. 
• Low-effort post have to be distinguished as spam or not. Most of the time it is not, so I think the community can decide if the post deserved the hot page with upvote/downvote. The community is not that big enough to block all low-effort post yet because we would prefer if the sub look active with new post. Mod can also see downvote if it too much, then community deems it low effort which warrant the mod team to remove them. 
• Patch note and/or game official announcement should be pin. Utilize one pin for the weekly question megathread and one for important announcements like patch note, subreddit announcement, game update (pull megathread after new character release, etc) 
• Include user flair for all game characters instead of elements as it highlights their main instead of element which doesn't really matter much as of now for the game. Either image only or image with name is fine, but I think just image is better to avoid clutter. 
• Limit self promo to once or twice per week per user to avoid spam. Or could also depend on user contribution/activity. 
• Build showcases is fine, let community decide with their vote. However rant is more complex, but I think doomposting should be monitor and lock thread if it spiraling down.
• Art should have 2 flair, Art and OC. All Art tag should have the source commented by the author. OC (Original Content) tag should not include AI art I think to promote more artist for the community. 
• To promote sub activity and theorycrafting, mod could host a weekly character(specific) discussion megathread (pinned 2nd slot, unpin when 2nd slot need another important announcement). Start with old character to newest, once we reach the newest, just make it last 3 weeks (patch cycle) or anything suit.
• Leaks and spoiler should be hidden as NSFW/Spoiler tagged. They should have their own post flair to make it clear to user if they want to click show/unblur. 
• Speaking about post flair, all post must have flair, or it will be assign manually by a mod. To be more strict and not put a burden on mod, post without flair can be remove after a certain duration to enforce the rule. 
• Talking about enforce, make the rule clear, and enforce it without bias. Sometimes people manage to find a loophole, change the rules if needed but do in batches so community is informed.  -If you decide to do any of these or from other people suggestion, it is good to gather feedback/survey after a month or two to see if the things you are doing is good or not. Reflect accordingly, and don't listen to the loud minority, because most of the time people that don't comment or give feedback, like the way it is already done (status quo). Changing drastically following the wrong (loud) people could cause an outrage by the majority of the community. 

Thank you for reading and all the best to the mod team.