i think this set up has real potential man verry pretty! have you thaugt about hanging the lights vertically between the plants? i think that would work very nice in this space.
and about the plants i think they got burned by the nutes or something, if you have a good fertilized soil you can wait 2-3 weeks before giving nutrients. i use 3 liter pots (3gallon) and water them with 1 liter water every watering and then wait for it to dry completley before watering again. When the soil is almost dry and you barley feel any moisture when you poke down your finger, then you know they need water the next day. I water them the frist thing when lights go on by first giving them plain tapp water 1/3 of the pot size, then wait untill night and give them same amount again but mixed with nutrients. I've heard they get shocked if you put nutrients in dry soil and that they sould drink water until they are not thirsty anymore and then slowly take up the nutrients after
but i am a beginner aswell so i might be wrong but a experienced grower told me this is how you do it and it has worked very well for me this far!

also again! i really think you should hang the lights down vertically, and seperated 1 by 1 so you could adjust them as the plants grow. because then you wouldnt need the reflectors and all the lamps would use 100% of its light. with cfl the lamp needs to be verry close to the plant for good results, i have mine about 5cm from closest plantmatter

Other then that i think this grow cab look awesome! someone mentioned the foil making hotspots but i dont think that is what troubled the plants, just a little over loved is all

really hope it works out fine im sure youre next grow will be fantastic! hope this helped and im sorry if my english isnt 100% hehe

blessings and love <3