I think the first step to take on its on clases/certificates.
there is no much variation on what to use on each class, cause if you dont follow the path that most people take your class will be useless. Also certificates would be a good idea to rework, they are all based on pre awaken classes and they do not provide any boost to awaken classes. i believe most of players use certificates cause well.. why not?
I also believe that there is a lot of KP's tree that can be adjusted in order to let you choose which path you want to take on, for example an assasin. right now is burst or being bursted (on that class) so for example ytou can give assasin players an option like ok you can pick the oneshoot build but in order to put kps on burst things, u gonna lack another stats, and viceversa if you pick long term fight lacking another stats so you can "balance" ur class. This using this class as an example.
Talking about certificates, you can try to make them work different, maybe only 3 needed for the p-atk buff iinstead of 4.
I would also like to recomend to remove all the p crit rate certs/kps since we already over cap crit rate/m-crit rate on most of the classes (except for healers that they need them still)
I dont think that disabling smoke bombs and transformation items will help to improve the pvp state for the same thigns that have been said already. Antor and pike been like this for years and now that its been used suggest a change/adjustment which i dont believe its fair for people who has been testing, trying to change the meta game etc.
Maybe it is not the trend to add this suggestion but would be also nice to give something new to Couples, could be even potions, or atleas make the buff last longer, could be also like pod buff.