These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
But it goes right back to heartbreaking in "The First Time," when Blaine's age got retconned to sixteen and he slept with Kurt. Six words: "I wish it was with you."
The Warblers constantly complain that Blaine's hair-gel has soaked through his skull and given him brain damage. In "Nikos," Blaine gets a concussion and David panics because he doesn't want Blaine to get brain damage.
When you crossposted this to another site, you added to the warning that "Don't count on there not being actual assault later on (physical or sexual)". So, umm, please don't make that stalker guy do anything TOO terrible to Blaine. He's broken enough already.
(You actually made me go Mama Bear over a character I usually hate OTL.)