to keep it short and brief. Everything is wrong. You need way more lumens from a light source. Ie get a new light and put it much closer. T5's are the best and kept 2 inches from plant top at this stage. Your 35 day old plants, look like 3 - 5 day old plants. NEVER use nutes, until two weeks after sprouting, and very mild feeding on the first nuteing. Never use miracle grow, it leaves deposits in the plants and soil. Your brown marks and dead plants are from nutes, its called nute burn. The seedling carries enough nutrients in the seed to last them two weeks from sprout. I would suggest going to 18/6 light cycle, I know people who use 24, but im an avid believer, that a plant needs to reguvinate at least a few hours each night, maybe 20/4. Go to a hydroponic shop and ask questions there, they will have all the info and all the products you will need.
Long thin plants, means its stretching to reach a light source, if the light source is right, you will have a short and compact little plant, which is what you want.
Water when the surface of soil is dry, but scratching under the surface is still moist. Never let dry to the point where soil seperates from pot, and never water if the soil is moist on top, both will kill or severely stunt the growth.