Half the time her own guards and employees are trying to assault her as well; who the hell is going to join her party?
Yes, good.
The Orc enemy type is specifically set up as a rear-line buff-producing-machine. You wouldn't even need to change the code to add a whole additional combatant on Karryn's side, you could model his presence as a set of passive buffs that he grants by standing behind you, or by adding a set of temporary skills to Karryn that consist of asking him to do a thing this turn.
And in exchange, maybe any time Karryn is knocked down or out of stamina there's a chance he gets overcome with lust and tries to fuck her. Or replace the standard defeat scene for the floor with him shoving the other prisoners out of the way and carrying her back to his own cell for some fun.
It's very difficult to do a pure run, but not impossible. You should focus on Money and Strength ability increasing Edicts. I started with Ambitious Experimenter, on Secretary mod with no cheats. It cost roughly 2000 dollars to unlock all the Published Record under Personal which will net you an extra 265 dollar per day. Also, you want to unlock Prison Guards for Office and Self Paid Equipment to lower your expenses as soon as possible.
Personally, I prefer a melee build at first because it is so much easier to unlock and you can go back to your weapon later. Once you unlock Strength level 4 you can buy all the unarmed combat skills and which makes it very hard for the enemies to take advantage of you when you can one shot them. Just keep combat limited to 3 or 4 encounters and fix your clothes often.
On secretary and warden modes it's certainly possible, though the final (so far) battle with the lizard alpha is super hard and might require save-scumming to come out as a virgin. I don't actually recommend doing all the Publish Record edicts if you're trying to be pure anymore, because the increased income is fairly small and the data you give them makes Nerds more dangerous now that they can debuff you by telling everybody else your weaknesses. Make up the difference in funds by charging admission for visitors at reception if you're not worried about making people angry, or by (very carefully) working as a waitress if you're okay with a little more effort.
Maintaining purity in Prisoner mode might be impossible. Certainly unlikely on a first playthrough, and I'm not sure which combination of titles you should collect before making the attempt in NG+.
I fully understand that the main focus of the game is to send Karryn down the path of depravity. However, is that inevitable and the only recourse, or are there any future plans where this is not the case? A (fully functional) route or two where everyone ends up acknowledging that Karryn is the undisputed, all-knowing, all-powerful, master-of-the-fuckin'-universe that can complete any assignment unscathed (including being the warden of a prison of ill-repute).
Your main problem here is that the game is still in Alpha. You can't get to your big dramatic pure badass ending, because there is no ending, and being 60% of the way to a pure badass ending looks exactly the same as being about to fall into depravity at the 70% mark and finishing up as a whore.
However, I have no doubt that one of the possible endings to the game will require you to maintain Karryn's purity throughout. Every time she receives a top level gift from the Emperor she reinforces the notion that loss is not inevitable, that it will be difficult but she fully intends to resist temptation and guard her chastity and then when she's done here they're going to get married. Assuming that the Emperor doesn't turn out to be the true final boss or some nasty twist like that.
Although that line of thinking does make me wonder if there's a super corrupt ending in which instead of (or after) doing battle with the criminal mastermind down below, the Emperor sees what you have become and tries to stop the monster he has created, only for you to come at him with all the dirty tricks you've learned in the prison and turn him into your sex slave...