Don't say 'this may be hard to hear', just be direct. You believe simple sentences are often stronger than complicated ones. I agree within certain contexts, but within others complex sentences can shine just as well.
Focusing on the character first as context for the story is vital for a first person narrative, but in third person it is a choice made by the author based on personal preference. The event of receiving the letter is not very important, so it is referenced as opposed to indulged in mass. I agree that the loss of his parents would be quite important not to gloss over, but Blake is not the main character of the series and we are hearing Ren's third person perspective not Blake's.
To start the story with 'Yet here, he was', 'He wasn't like the others', 'this is why you should care about Ren, are you caring yet?' feels rather inappropriate for my story. The narrative could be just as good told from the focus of Ren as a character, but such is not my story, my choice, or my style.
To put simply, the critique of my choice to sparingly use purple prose for atmosphere, mood, tone and depth or my choice to focus on the world first then the characters, is to say, "Stories about a protagonist wearing a frilly hat are best, please conform to my personal preference and write the beginning of the story focusing on the protagonist's frilly hat."
I am quite aware that my story will not appeal to everyone's taste, but in critique I am much more interested in the execution and effectiveness of the narrative from a more objective standpoint. Things such as flow, pace, clarity, depth, immersion, maturity, artfulness, etc.
I believe that your suggestions are very good and important for first person narrative, but there are many styles and approaches to writing a novel. You have given me much consideration on the poising of my characters though, I will review the chapter and see if I can more smoothly provide context for who you are following in the story and where/what/why/how everything is going on.