Answer 1

an "-isimo" or "-isima" ending to an adjective is indicating an extreme. So, he took buena (good) and made it buenisima to pretty much say "great!"

Answer 2

HI Cali, not really

This is used for "oh, beautiful, great looking"

Answer 3

buenísima (con tilde)

Answer 4

gracias! the last 2 replies made my day!