Okay wow this thread is a mess.
First every
tractor supply and any other store that sells chicks is completely different.
Secondly what bedding did you have them on when your chick got splay legged? Many people raise chicks on newspaper but newspaper is far too slippery and can cause splay leg. Paper towels it wood shavings are better(be careful to get the larger wood shavings not the very tiny ones as they are more dusty and more likely to be eaten). We start all of our chicks on paper towels with shavings underneath them. Dog potty training pads can also work for very young chicks but once they chicks start scratching they must be removed or the chicks can get tangled or eat the pads as they scratch them up. Be extremely cautious if you use the potty training pads with the absorbent gel in them because if eaten it can kill chicks.
Now I think the employee you spoke to on the phone may have been referring to if the chicks that came in were sexed or not. Maybe not. I could be wrong of course.
Now about the sexing thing.
Feather sexing only works if the bird was specifically bred for it, so while you may have some minor luck most of it will be chance. Buff Orpingtons can not be sexed this way with any accuracy. While males generally feather slower each bird may have hatched several hours or even a day or more apart.
Vent sexing is very hard to learn, I have a friend who went to college for AG and he has been working on it for years but still doesn't feel comfortable coming and vent sexing my chicks for me. We hatch out multiple times a year of multiple breeds.
Furthermore when done incorrectly vent sexing can injure or kill a chick. I wouldn't suggest doing it.
Also any feed store that allows you to handle the chicks before purchase is at an increased risk for biosecurity (aka if someone with sick animals handles a chick-even if they don't know their animals carry something and you bring those chicks home you could expose your flock to any number of illnesses or diseases)
Next I would suggest removing both roosters from your pullets until they calm down. I would also not keep a rooster that has been showing people aggression.
Also where are you located?
Silkies can be very cold hardy however they are not labeled as a cold hardy breed and if your coop is quite large he may not have been warm enough. Some of our silkies do great in winter and others seem more sensitive to the cold and don't want to go out.
While their combs are good for cold weather their feathers aren't always the best for insulation especially if it's extremely cold windy or damp.
Think of it this way normal feathers are a windbreaker and the wind doesn't penetrate to their bodies silkies don't have that windbreaker although they do have nice insulation. Also silkies are much smaller birds so they will often cuddle up to the larger birds for added heat.
I have had one silkie cockeral that was people aggressive as a juvenile. We rehomed him and he was never aggressive in this new home.
While breed can give you a great idea of what a bird's temperament will be it can not be 100% every bird has it's own temperament. We have had wonderful silkie roos too.
Hatchery birds do tend to be more unpredictable in their temperament as they breed more for production than for standard of perfection which includes temperament.
Buff orping roosters are said to be great birds.
I'm sorry you have had a bad first experience but brush it off learn from it move on and enjoy your birds.
As for your splay legged bird. What color is she? Can she get around at all? Pictures please.
Also on a side note if you ever come up against another employee that tells you they don't care what you want. Report them to their manager and request different help getting you your chicks. That's ridiculous.
I’m sorry that happened to you. It’s a story I’ve heard all too often.
Tractor Supply does not care wether their employees know anything about chickens.
They’re more interested in wether they can drive a forklift.
It’s very unfortunate that some people are willing to BS customers though

I’m amazed how many people will get animals of any species and not do any of their own research.
I was reading books about chickens and lurking on BYC 2 years before I even got my own birds.
I highly encourage others to do the same! It’s very empowering to learn and teach yourself what you need to know.
It gives you the confidence that you can handle the basics.
Best of luck with your birdies!
Okay while I don't necessarily agree with everything you posted I do heartily agree with doing research research research before getting into anything. Whether it applies here or not.
So many people don't and then end up in big messes.
I do however agree that any store that sells chicks should make sure their employees know and do the basics. I also agree that stores that sell chicks should have each stock tank marked. Most hatcheries will mark the chicks' heads with a certain color for each breed. Of course that depends on the hatchery and breeds the store receives as well as what was shipped together.