Keeping/managing Order is one of the challenges of the game, the easiest one is to have a good amount of Control which is increased through edicts and then beat up some enemies to regain a certain amount as beating enemies actually awards Order, but there are also certain edicts you can use as an emergency buy to get a boost of Order, one of the first ones gives 25 or something
The minigames do nothing for Order or Control, they are mostly for increasing revenue or, if you're like me, getting Karryn to be banged when you're too bored to fight
About managing Stamina: upgrades to Karryn, also found through edicts, will help you a lot with that and levelling her up in it can certainly boost you
If you wish to get to the Boss without too much fatigue, pick a day where there are no riots so that you can get to the floor safely and skip doing any minigame
Some room before the Boss is usually an abandoned Guard room where you can sleep to get rid of accumulated Fatigue, there is a chance that you may get ambushed midsleep but honestly it only ever happened to me when Karryn masturbated so I believe it is pretty safe to use
After that simply try to avoid enemies to the best of your abilities
Remember that running away is still an option and then when you get to the Boss, good luck
Last few Tips:
>Do not make Karryn a jack of all trades, choose 1 maybe 2 stats to farm. This is usually done by using only certain attacks or only the actions that use that stat, so always attacking with the advantageous attack is not actually the best way to go
>Low Order actually increases Income, I know, what an asshole design, I love it. So while your Order is at max, prepare to be in the red even when you're currently cutting on all spendings, I fell into that trap myself