I’ve been trying to replace “guys” with “folks”, although I sometimes forget. Having grown up on Electric Company, it’s a hard habit to break.
Yes.
When I was managing a small group which had two females one male I asked all three if everyone was Ok with me saying “Morning guys!” or “Can all you guys come into my office?” and they are were perfectly Ok with it, and the two females seemed surprised anyone wouldnt be.
"Gals’ can be used in a informal situation “Hey how about us gals get a drink after work”? same with “girls”. But neither should be used at work except among female peers. Mind you, if there is still a steno or secretarial poll, the traditional term is “Girls in the steno pool” but I think that should be used with caution. “Boys in the band” is similar. Traditional but used with caution.
“Morning everyone”, or “morning all”. Works fine by me. ("morning Jo’s 'n ho’s may get you in trouble)
This is best done if you’re wearing your “I LIKE IKE” pin on your sport jacket 
Like this?
How about “Guys and Dolls”? Or would that be rocking the boat?
I would say, “good morning”.
That sounds very informal to me. Not that I’m super formal at work, but i wouldn’t say that. It’s funny, because i work in a super conservative industry (insurance) but we are a hell of a lot more gender-friendly than the IT industry. I realized this when i was at a mostly IT party, and a non-binary person said that their manager addressed the group, “good morning, ladies, gentlemen, and Chris”. And i realized i hadn’t heard a gendered greeting like that at work in decades. Literally.
I agree. The point I was making is that there are degrees of formality that depend on the setting, determined by things like the culture of the work environment and whether you’re greeting a small group that you know really well. And yes, “good morning, guys” or “hi, guys” is on the most informal end of that scale. But not necessarily inappropriate in the right kind of business or social setting.
Well, you know computer types are used to a world where everything is ultimately binary!
It’s funny, but that one would probably be more likely to bother me because of the strong gender imbalance. I watch some things on YouTube that are likely to have a pretty strong gender imbalance. When the person uses “guys” I tend to think they imagine their audience as all guys. It tends to be reinforced by other uses than just saying “hi, guys,” like “some guys do x.” That seems more gendered to me. When there’s a pattern, it definitely bugs me.
“You guys” is probably the least gendered use I can think of. It seems like an idiomatic phrase to me, with little gender association.
And as for the OP, I think just saying “good morning” is a good choice. Oh, and I recommend against y’all if it doesn’t roll off your tongue. It can sound really fake.
If it’s informal enough to say ‘guys’ at all then I think it’s fine for a mixed crowd. It should only be used when there is a level of familiarity that would preclude any misinterpretation. There are plenty of neutral alternatives if it’s ever an issue.
I’m in my 50s and I haven’t considered “guys” to be a gendered term for ever. There were examples of gendered use in pop culture, like “Guys and Dolls,” but in real life, we never used “guys” as a gendered term.
Even the women or girls around me addressed each other as “you guys.” “You girls” would sound odd and old-fashioned.
I get where you’re coming from here, but I’ve watched quite a lot of this guy and read some of his material as well, and you can hardly imagine a more respectful, socially adept, and fair-minded person. His views on CRM, for instance (crew resource management) emphasize the critical importance of both cockpit discipline and an atmosphere in which all crew members treat each other with respect yet are not afraid to communicate their opinions, no matter your rank, experience, or anything else. To the extent that there was any gender discrimination in airline flight crew, he’s the sort who would be actively working to correct it. His “hi, guys” is just an attempt to build an informal rapport with his viewers, nothing more. Sometimes a cigar is just a cigar, sometimes “hi, guys” is just a friendly way of saying “hi, everyone”.
How did you get hold of my lectures?!
This is pretty much my though. Guys isn’t gendered but it’s pretty informal for work.
Hey Folks:
Over here in California, the terms “guys” and “dude” are pretty much gender-neutral, no matter how the words may have originated.
“Bruh” and “Bro” are starting to become the same, but usually, “Bruh” is more of a start to a sentence, like OK, or Um, or Like.
Was that really necessary?? 
My favorite song in the show! Gotta love Stubby Kaye.
Fair enough. As I said, it bugs me when there is likely a gender imbalance in the audience, and there’s a pattern. It sounds like it wouldn’t be a pattern with him, which is great.
Joke from the Honeymooners:
Ed Norton reading a newspaper: “Bus Stops With Jerk; Jerk Gets Off”
I just say “hi, gang!”