Regarding your main question, it seems to me you already have a fair understanding of "classical" music. As you say, music should be opinionated. You are entitled to your preferences: it's a free country.
Although the performance of Baroque music with Romantic expression and emotion is something I would not necessarily agree with, you are perfectly entitled to do it.
As a fellow pianist, I admire the playing of Ashkenazy (whom I happen to hold as my favourite), preferring his renditions of Chopin, etc, to other pianists and this is because I appreciate his technique and interpretative style. I don't just say Ashkenazy is the best to sound clever, it is really my opinion. If someone believes otherwise, that is their prerogative.
Each to his own.