A good rule of thumb for thinning is only remove about 25% of total leaf mass.. You got a little carried away but look at the manifold you made.. Really no harm done just slows em down a little.. About bloom nutes, I used to think like you, start them when you flip.. but have learned to use grow nutes until 3 weeks into flower.. then mixing 50/50 grow/bloom..
Then bloom nutes.. Now for the reasoning... Bloom nutes are just that, nutes for blooms... when you flip you have no flowers at all.. you need to grow some before you feed them.. I hope this makes sense I had carpal tunnel surgery and oxycodone is messin with my head or the ogk is helping.. With steer manure in your soil you have to be careful with additional nutes.. I'm basically doing the same thing and have just a slight nute burn on my newest leaf tips...You may not need additional nutes..