A hard one.

I am confused by a couple: "M T C" I'm not sure how that signifies the corresponding phrase; "X+X=>" to me reads "ex plus ex equals greater than" I get that 'x' can stand for wrong but I don't see how '>' signifies right. Would "W+W=R or x+x=[unicode character for the tick symbol - if PuzzGrid supports it?] be better?

The date you have entered in Roman Numerals is 3888. I assume you meant MDCCCLXXXVIII, and I think you mean to define it as the longest date in the common era SO FAR expressed in Roman numerals?

Your longest word doesn't word wrap when the puzzle is loaded so it gets truncated. I would suggest modifying it to include a couple of hyphens and manual returns.

I liked the Grid. There were just those few things that made it harder to solve than I think you intended.

Thanks :-D

Empty sea, > is commonly used to mean moving to the right.

The rest of your comments, yeah, I agree. Tenuous links made worse by errors