1. It might be fine if it was actually acidic but they always use shitty canned pineapple which is just loaded with sugar, and doesn't even taste like pineapple. And I don't like sweet foods as a meal in the first place, was never a huge fan of pancakes or jam on toast.
2. Avocado does not actually taste of much, it's more the creamy texture I like, but if the avocado is not fully ripe you don't even get the creamy texture, and it's really not great without it, so I can sort of understand.
4. Like green olives on occasion, hate black olives. Also they are overly salty. Not something I would eat frequently.
5. You have not had good octopus
I had some really tasty octopus braised in red wine in Greece and you would not have been able to tell it was octopus. It had the texture of a tender steak, and the taste was like nothing else I've had. I was amazed as I expected it to be more like what you described but it turned out to be one of the best meals I had the entire vacation. I figure people just suck at cooking it properly.
6. I don't know what shrimp/prawns you have had. I think here in Norway we have better prawns than many other places as my dad's wife says she can't get freshwater prawns like that in Singapore so she loves eating them whenever she comes here. And they don't have a strong flavor at all, so I can't see anyone outright hating them. Especially not a mayo lover since they go great on toast slathered in mayo. Maybe you just had bad prawns, IDK.
Agreed on 3, 7 and 8 although ice cream sandwiches can be good (the ones that have a soft and slightly chewy cookie exterior are great), I am really not a fan of hard cookies in my ice cream.