First of all, remove any in-game content that is not SB related and make VIP club our pet leveling hub again and increase the pet experience gain to 3x the amount of Suer. Instead of taking content maps from other game, re-use SB map resources: (CG,Scylla,Nemesis,LV59 map)
Scylla as leveling map in place of DV.
Nemesis as PVP map as our new PVP zone probably for 70+ cap if there is a plan to expand.
Hard and Hell mode NPC for every dungeon placed next to the respective NPC that gives normal access to those map.
Mini games, hourly compensation for staying in-game for extended amount of time(increased drop rate, exp rate, gold drop rate etc. that caps at certain percentage).
Special monster hunting that spawns in random places in specific map at random time with rare drops that can be used in crafting.
Better crafting system.
Better RP system, remove RP from player kills and make them join BG and finish the class specific quest there to get PVP rewards ( 10 pcs 1k RP chip, 10 pcs box of Cybercluster II, 10 pcs Hypovial Pack).
Play through quests starting from the beginning up to the last quest of the official SB game and make a new story in line with the main storyline concept.
Fix all the small bugs.
Better UI/UX for the main SB website, Launcher, better donation system and place relevant stuffs in item mall such as Newbie Starting Pack, sell old bikes and costumes instead of putting repetitive stuffs in loot boxes, use the loot box for brand new stuffs that people will actually like.
Useful daily quests.
Napalm CD reduce to 1 hr, Ultimate CD reduce to 5 mins, Revamped ultimate for some classes. Indicate the scope and limitation of what Vivi can and cannot do so the community can give better recommendations and to avoid having to scan through/write wall of text such as this.