As a server/community manager for other servers one of the best ways to improve community and make it bigger is by doing giveaways such as Picture Perms , Testers (not for this server tho), Robux, Nitro and so much. You can make requirements like inviting 5 people or 10 into the server before entering or become lvl 5 to enter
#Giveaways
fallen viper
royal badger
They already have a channel for this #🎉│giveaways
Everything you said other than tester has been given away.