too many characters for my taste and i'm not sure about style.

Initially I found the style too hard to follow and the characters confused me but that was because I thought I could jump in the middle or so which for this fic doesn't work. But when starting from the beginning I was really impressed. If it's well done, I really love this kind of style. Not for everyday reading but every now and then it's neat.

was it necessary to made Dean gay? (just out of curiousity question).

It is a plot point insofar as it causes estrangement with John so I'd say for the story it's not just gratuitous.