Not really about food but drinking something while eating. My daughter ate some 'temperature hot' on a few occasions and we're telling her to drink something - water, soda, milk - to cool down her mouth but she refused to do it. She's always had this thing about eating her meal first before drinking anything.
I always have something to drink on the table when I eat (a glass of water, tea etc.).
However, I only drink when there is no more food left in my mouth. I have seen people drinking while still having food in their mouth; they hadn't swallowed all of it yet. I don't do this because I don't like the mixing in my mouth. So I drink during meals, but I either put food or the beverage in my mouth, not both at the same time.
The hot food problem is an exception though. If it is hot and uncomfortable enough, I'll drink something to cool down nevertheless. I try to avoid this situation. I prefer my food not that hot anyway and rather wait for a while to let it cool down a bit, so I'm comfortable with the temperature in the first place.
When I was a young kid I was a picky eater and much like folks describe on here, food can't touch etc. I would only eat one item of food at a time, all rice till it's done then all meat till it's done or whatever. However this is an aspire trait I've entirely outgrown. I am very much the opposite of a picky eater now and love new combinations.
Like you I have outgrown some of my picky eater traits. I'm still careful about new combinations though. If there's a new combination, I prefer to try it on my own terms to figure out if it is okay for me.
Also, I hate eggs, in any form. People keep on telling me eggs don't have a taste, but they do have a taste, don't they? Especially the yolks? Especially in Europe? (Scrambled eggs in the US, I can do if I'm in a setting where I can't get away from eating them, as long as there are enough potatoes to cancel the taste and texture)
Of course they have a taste. My problem with eggs is rather about the texture though. But I am more accepting of eating eggs than I used to be. They still have to be "right" and I cannot eat all the variations (for example, it is very important for me that boiled eggs have the exactly "right" texture, so I can eat them, which depends on the time of boiling).
I never minded mayo or things touching or anything like that, though it was hard to get me to try new foods (as with most kids, I suppose).
The 'weird' food habit that I had that lasted me until I was at least 15 or so was that I would 'dissect' all of my food.
For instance? McDonald's chicken nuggets. I would tear off all of the skin, eat the skin, and only then would I eat the 'middle'. I did this with anything with a skin, including grapes (I'd peel off the skin with my teeth like you would a banana, starting at the little hole where the stem came from, for every individual grape), and even for some things without one. I'd just eat the outside first. Like with Twinkies or Oreos, I would eat the 'cake' or 'cookie' parts of all of them and then leave myself with a big dollop of icing.
I did the same thing for a while with several kinds of foods. Grapes, like you mentioned, but especially fish fingers. This is similar to the chicken nuggets you mentioned. The difference is that I would eat the "middle" first after tearing off the skin of the fish fingers with my fork and then eat the skin at the end.
I also did this with Ferrero Rocher and similar chocolate candy. I found this picture that shows my eating process of it quite well:
Ferrero Rocher - Wikipedia
Coming back to boiled eggs, these can be dissected too if they are hard-boiled. I did this as a child as well. I hated the yolk of hard-boiled eggs, so I would only eat the white and leave the yolk on my plate. However, my parents weren't accepting of this behaviour and insisted that I ate my eggs either as a whole or not at all, so I stopped eating boiled eggs.
Another rule I had was that once a dish was introduced, this was the only "right" way to do it. I couldn't handle changes of the recipe afterwards because it was still called the same although it wasn't like it used to be.
Funnily enough, I would accept the change if it got a new name and introduction and therefore was a different dish. It was more about the dish staying the same than the taste itself. Even if the variation tasted well, it would be "wrong" nevertheless and I would complain.
