Tips & Hongbaos, what's acceptable?

I notice there’s a thread on giving kids hongbaos with some OT comments on weddings, but is there some kind of a standard for the following, from a non-relative?

Someone has mentioned that giving what you are comfortable with is OK, but there is such a thing as giving much too little and raising eyebrows. For example, US$50 for attending a Singapore wedding is fine, maybe even a bit generous. But US$100 is the bare minimum for a HK wedding, so it’s a little hard to guess. Sometimes a gift of somewhat less value is fine, sometimes not. And hongbaos are expected in the Hong Kong office during the Chinese new year, but certainly not in Singapore. Any advice?

I ask because I would be expected to give money in the following situations in Hong Kong and/or Singapore, but have no clue about here. Luckily I don’t believe I have any relatives here to make things more complicated…

Tip to person delivering something to the home?
Tip to movers?
Tip in a restaurant? - when you pay by credit card, some receipts don’t even have a space to write tips; I filled in the tip section for one restaurant and they didn’t bother to charge it to the card.

Hongbao for a new baby, your own or spouse’s colleague?
Hongbao for a new baby, a Taiwanese friend?
Hongbao for a birthday celebration, your own or spouse’s colleague?
Hongbao for a birthday, a Taiwanese friend?

Hongbao for receiving a wedding invite but not attending, a colleague/spouse’s colleague?
Hongbao for receiving a wedding invite but not attending, a Taiwanese friend?
Hongbao for a wedding, a colleague/spouse’s colleague?
Hongbao for a wedding, a Taiwanese friend?

And during Chinese new year:
Hongbao to the security guard(s)?
Hongbao to subordinates at work?
Hongbao to equals at work?
Hongbao to unmarried colleagues/spouse’s colleagues?
Hongbao to children of colleagues/spouse’s colleagues, if not encountered?
Hongbao to children of colleagues/spouse’s colleagues, if encountered?
Hongbao to children of Taiwanese friends, if encountered?

Should anyone else expect to receive a CNY hongbao? What about at other times of the year?