being in too small of a pot isn't a real thing and it certainly wouldn't cause damage like that. I finish plants in half filled solocups sitting in a tray with a thin layer of water in the bottom and they never show any health problems or disfiguration or discoloration. a plant just grows smaller in a smaller pot, "tight shoes" isn't a real problem.
your plants are firstly overfed and overwatered. thats what's causing the majority of those problems. that ultra bright yellow is iron or sulfur IF it's a deficiency at all. see the dimpling from the thickness of your leaves? that means they're full of nutes and water. the slight hardness on the end is likely from too high of feed. crusty parts on the little blade parts on the sides of the leaves are too high of feed. those plants are mega overwatered or in mega high humidity. you need to let them dry out, feed no nutes for at least 2 feeds, and not spray them with anything and then come put up more pics once they stop that soaked drooping. be careful with crazy sounding advice. 90% of the time first grow means overwater, overfed, overbabied. some of the advice you've gotten was nuts and prolific. not everyone here knows what's up regardless of post count. the ed rosenthal grow book mentions how to read leaves for feed and most other questions you'll have but it's really lacking in feeding by ppm/ec and nutrients out there so buy that with that in mind.
EDIT: the yellow tips means over nuted. the black leaves mean too much nitrogen, shoot for deep green although most of the plants nitrogen(80%) is taken up in the first half of life and it honestly doesn't really effect end harvest as long as you don't burn. you'll see plenty of pros with BLACK leaves from as soon as the plants mature enough to throw them. some is genetics also, so be realistic. you can pm me and take my email so i can answer you faster if you want but im confident i can turn those around for you with little work. they have a lot of health in them still. also, upturned or crusty leaf edges = overfeeding, the dry ends of the leaves and the hard curl is from overwater or soil holding too much moisture(although ive watered plants in soil that needed once a week and they didnt droop in a fabric pot)or major humidity. these need to dry out the most. yellow twisted deformation comes from overwatering, wrong ph, or a fan really close can cause that also(usually with browning/yellowing between the veins of fan leaves near it). please don't do any more crazy suggestions, they are not right or even close.
I've been figure things out with the help of all your suggestions and comments. I believe what ive done was 1. Overwatered, 2.gave Nutes to early, & caused a nut burn. The plants were badly rooted at the point I did the above. My ph in my log after I went back and reviewed was andnis running b/w 5.8 6.0 I let it creep up slightly in 2-3!days then bring it back down. 
