Don't worry bout the pistils turning orange, that is supposed to start happening a lil later than I think where you are but it's probably just from stress. Another reason would be pollination and we know that's not it. It's probably the stress from the nute burn. Not a big deal though, she's gonna fatten up.
I've popper over a hundred seeds myself the last few years and once in a while you get a real finicky plant. My most finicky was Dojaberry, a blue berry X double purple doja cross from Outlaw genetics.
Seemed like I burnt the shit out of her early using just a moderate dose of nutes and even when I dialed it down she still looked like shit from all the scorched looking leaf that curled up and was very brittle. It kinda crackled off when you touched it and looked like shit untill flower. I started dropping the feed down to 50% just on her and was making her, her very own one gallon mix at half strength when the rest of the plants would suck up the ferts just fine at 100% recommended dosage then I bumped it up even a lil more.
The Doja Berry filled in nicely with dense purple nugs and thick orange pistils despite the ugly yellow brown burnt leaf around her. Smelled like a combination berry and cough medicine to me. Was one of the most purple plants I've ever seen and run all the way through in warm temps. But the point is, I guess, shit happens.. plants grow and with hybrids variations from the parent strains are going to happen, some shorter, some taller, some greener, some purple, some heavy yielders, some piss poor yielders (these variations are called phenotypes or phenos for short).. with seed ya never know what you're gonna get except that its a mix bag of lottery like chances with the winning results being characteristics of mom and dad, some more like mom, some more like dad, some 50/50.. the only way to find out is grow.
Outlaw Genetics- Dojaberry
Look at how ugly the leaves are
Now look at the Bud
I haven't done Auto-flowering myself because I want to keep (clone) the ones that are special, and I understand you cant really do that with autos. Fortunately for you, once this is over you'll have experience what it is like to grow something difficult and you'll learn a great deal about how much of a pain in the ass one "pheno" can be. But the next seed could be completely different, or the same. It's the game of chance mother nature brings to the table that we all play.