A little research might be in order before spending $1k+ on a knife, or maybe start with something a little less serious but that's just me....a lot of your questions have been answered thousands of times, just an fyi. Maybe it's worth it to read the whole Mazaki thread.
Regardless here are some quick responses.
Patina will always cover up the damascus pattern to some extent. I will attach below a picture of how a hatsukokro komorebi damascus looks new, and with patina.
Camelia oil is used for longer term storage, not active use. White vinegar would remove patina yes, but then you would have to actively neutralize it before it creates its own patina. Baking soda and water or barkeepers friend will also work, sometimes even lemon juice is enough. Remember to wash normally after to neutralize the acid.
If you really do not like how patina looks, do not consider a carbon steel knife. They will patina, and patina heavily and if you don't want that, you will have to clean it after almost every use. If you want a bright shiny damascus, get a stainless damascus like a sukneari, that will not fade over time or patina.
I like natural patina appearances over a forced one, but that is just me. You can force one but again, it will cover up your damascus quite a bit if you etch it.
For that blue look that you mentioned, best for me to achieve that is cutting hot meat, and onions.
View attachment 246833
With some very light patina after 2-3 uses. Can still see the damascus but obviously it is covered up:
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You could also etch the knife like this, I believe this is with ferric chloride. Will be much more resistant to big color changes and patina...but of course it's black. So.
