The phrase is: “for all intents and purposes”, not “intense and purposes”.  I mean, the second one doesn’t even make any sense.

my boss says “intensive purposes” and it reeeeeally makes me crazy.  and she’s a smart woman who i really like a lot!  but that… oh my goodness, it’s nails on a chalkboard.

“nails on a chalkboard” HAHAHA totally agreed

it drives me crazy anytime people mess that phrase up