YES, kawaii can be used for all these things - But Guys, PLEASE don't say it for cool and nifty and for family members and all that!! Only little girls can say everything's cute!! You'll get wierd looks!
SirGuy: "Well, you're new Look's rather kawaii mister Male! *giggle*"
SirGuy: "I have to hang with my kawaii bro, so I'll be seein you later!"