This was one of the best rule discovery puzzles i've encountered.
I managed to solve all of them except the second one from the left on the bottom (and looking at the solution... [V jnf abg rkcrpgvat bcrengvbaf lbh pna'g rnfvyl rkcerff va n fcernqfurrg]).
The top-right-most one took some errors to solve, [naq V nyzbfg qvqa'g pbagvahr gb gur guveq vgrengvba]. The second one from the bottom on the left also took a lot of time [orsber v abgvprq gur ercrngvat havdhrarff], the rest weren't very difficult but still very interesting.