I'm smiling reading this because he sounds just like myself and my autistic peers. For clarity I will repeat (not so much for you, OP, but for those who take issue with autism being suggested) that I'm not assuming he's autistic, and it isn't a bad thing to wonder if he is. It's a normal neurotype. To me it's like wondering if someone has ginger hair (clumsy metaphor but hopefully makes my point that it's a neutral characteristic in my opinion, not a pathologising thing or a doom and gloom prediction).
OP, the sensory "sensitivities" (super-tasting and intense experience of noisy and busy spaces) are very typical of autistic people. As is becoming overwhelmed when feeling strong emotions to the point of finding verbalisation impossible or very hard. Feeling like "words freeze" particularly stands out as something I fundamentally recognise, and I know many of my autistic peers and clients (I'm a support worker) would, too.
Rewatching favourite media (beyond the expected repetition expected from a young kid who loves something), and particularly the seemingly natural and striking ability to memorise and quote lines and scenes, is classically an autistic trait, too. It is also very familiar to me that he seems to derive great joy from doing this. Does he sometimes seem to use lines from his favourite shows/films in conversation or to express himself? Many of my autistic peers and clients do, though not all.
Contrary to popular misconception, autistic people very often have a great sense of humour: sometimes it's a little offbeat (not always), often it's very "quick" like you describe. There's a misconception that autistic people always struggle with humour and sarcasm etc., and it's simply not true as a rule. My experience has been that autistic people typically are very witty, and that misunderstandings and literal thinking can at times obscure that inbuilt sense of humour or cause miscommunications.
My personal advice would always be to seek assessment if you suspect autism. This isn't because it's a negative thing to be autistic, or because it needs "treating", or to force a label on a person. It is because we never, ever know what the future holds, and while an autistic person might do fine without external support for any length of time, there might come a point in their life where they do need support. Could be access to services, could be a sick note for burnout or overwhelm, could be a support worker or accommodations at work or education, could be accommodations/a "VIP passport" for hospital treatment, etc. My experience as a support worker (of a decade, now!) has shown me how rapidly and unexpectedly a person might need input they didn't previously need, and how hellish it is trying to get an assessment for autism while in crisis, to access the support they now need.
A diagnosis can also help massively with sense of identity, answering questions and finding community as an autistic person gets older and develops their own independent life.
A diagnosis never needs to be shared with anyone. It can remain completely private until/if/when the person wants or needs it to be shared.
Again - he might be neurotypical, and this essay be all for nought!!
Wishing you all the best :)