It's very common here in the UK to use "guys" with zero connotation of gender. My daughter's gymnastics teachers (an entirely female class) uses it, my daughter

It's very common here in the UK to use "guys" with zero connotation of gender. My daughter's gymnastics teachers (an entirely female class) uses it, my daughter's dancing teacher (ditto), my wife with my two daughters, my female employees with our group as a whole.. I veer towards "folks" to play it safe and in respect of people I know who feel strongly about it, but it's quite a modern American concern in my experience. I find "gang" an odd alternative to suggest in language delicate contexts (i.e. where "guys" is already causing offense) considering it relates to crime.