Instead of 4 extra enforcements you could add 8 extra characters.

Your entropy is (somewhat simplified)

One 8 letter word: 15 bits

1 uppercase = 3 bits (or even just 1 bit, people capitalize the first letter)

reversing 2 rules above: 1 bit

replacing two characters at random places: 8*7/2 = 4.8 bits

inserting 2 random non alphabet characters: 40^2 = 10.6 bits Total: 34.4

The entropy of three medium difficulty words is log(4000^3) = 35.9

Instead of memorizing K!ybo4rd it could be mykeyboardisblue.