I agree that they should make shai better to play, but every single take you have would only make her more problematic in the areas she's already the single biggest problem in, large scale.

So let the large scale players deal with it in large scale. Or cap her buffs in large scale. Most players aren't PvPers in this game anymore so saying it affects large scale PvP is a useless argument unless you're going to suggest fixes.

Do it better is her E buff, having 10 more ap does feel lackluster when you look at it as just that, keep in mind you're passing that ap and special attack damage to allies, that goes around gear caps in node wars and siege, and keep in mind it's 10 allies. 
with the ap and dr changes they made it so you can't stack ap affects, that's why it doesn't stack, and honestly having people running around with a combined 70 extra ap is absurd with how things are balanced now. 

Again, you're looking at this only through PvP (the minority of players). You're being buffed for and your opponent is being buffed for the same amount. Now that buffs don't stack, if you are dying faster to the enemy they are just better than you. No excuses.
 
the rebuffing can be quickly and easily done with cancels, and I rarely ever run into issues where I can't find somewhere to spend 2 seconds to do so. also having the buff last 3-5 minutes is absurd, the only way to justify that is if it's only for the shai, and all other players have the normal length for the buffs, but in doing so you lose your easiest timer for seeing when to rebuff allies. 

Rebuffing is the single greatest time waster in PvE. Other classes do not spend (definitely more than) 2 seconds every minute to buff up, and they don't have to worry about buff timers at all. They simply use their skills and their addons do the rest. Which, mind you, their damage percentages per AP are much higher per skill and their skills are much faster so they do considerably more damage per minute than Shai does. You know when to rebuff allies by seeing their HP bars, or they can make it so the buff on Shai lasts for an hour and the buff on everyone else lasts for a minute and give the Shai an icon saying "hey you're buffed" and keep the cooldown timers the same. Absolutely no reason for Shai to need buffs to perform at the same level as an unbuffed any other class in the game.

A toggle based version would be convenient, it would definately need to be implemented in a specific way though, and I can't think of a good way to go about it without it also being problematic.

I am not seeing the problem. If yes'd up for NW, disallow the toggled buff feature. If not, it doesn't really matter now does it?

you gotta keep in mind that shai is LITERALLY the most impactful class in node war purely because of the buffs, the only way to get her out of the backline is to harshly tone down buffs and to make her florang skills better. 

Shai is no longer the most impactful class in nodewars. She used to be, before they removed buff stacking, but now she's a nice to have, but everyone else also has too. But I do agree that there is no reason for her to be buffed only to a point where she is as good as another class can be while unbuffed, while absurdly increasing the attack speed of other classes beyond their normal ability. She should be by default as good as other classes and benefit minorly from her own buffs so as she doesn't even require them to do basic things. Shai will never not be a backline class. Her damage and AOE is way too minimal. Yes, you can take her into BA and you can 100% a standing target that isn't doing anything to defend itself from 100% health to 0, but that's not how PvP works, now is it? You're rarely ever going to catch anyone with your kick or your eat this skill. The Shais in AOS that get kills are either up against low skill opponents that don't know how to rotate their protections or they get lucky where someone misses a grab and then they manage to get a kick out in the specific circumstance where they've already buffed to max and then landed their CC. The only exceptions are the very top 0.001% of Shais who actually belong in the Master Class tournament and who have been PvPing for years.

So yes, tone down her buffs and make her actual skills do more damage per AP, give her 1 hour buff timers on self, and keep the 60 second buff timer on friendlies. It's more than time for her to be a normal class, especially after they gutted how buffs work in this game. She needs more attack speed, more damage % per AP and more protections.