Assuming you do not apply for a reentry permit before you leave, the maximum stay is 1 year. If you apply for a reentry permit before you leave, the maximum stay is 2 years.
If you wish to stay longer than two years, you will need both a reentry permit and a returning resident visa. You must apply for the reentry permit before you depart the US. You don't necessarily need to receive it before you leave.
If you stay longer than 2 years, there is no guarantee you will be able to get a returning resident visa.
Note: your US green card may be taken away if your travel record suggests that you reside outside the US more than in the US. So, coming to the US for two weeks every 11 months will at some point result in cancellation of your green card and an inability to return to the US using the green card.
Yes. Minimum for 5 years to get green card
yes
No. However, if you will stay outside the U.S. for more than six months, you need to apply for a Re-Entry Permit before you go, or you could lose your permanent residency. See the link below for further detail on international travel by green card holders.
approx. six months.
No, it is not mandatory for green card holders to posses a machine readable passport (as the green card is machine readable).
Of course you can. I think you can go uptil 11 months. On the 12th month you lose your card
No - a Green card means your a permanent legal resident. ESTA is only used for Visa holders and waivers
Yes, they can.
Green card holders can travel abroad for a maximum period of 180 days on each trip. If you need to stay outside longer for employment or religious purposes you should apply for reentry permit using application travel document, the Form I-131 which is valid for 2 years. Also you can use the Form N-470 meanwhile to preserve residence for naturalization process after a year as green card holder in US.
A child that has a green card cannot stay more than one year outside the USA. A green card holder has to spend at least 6 months inside the US each year.
Yes
Yes
Yes they can. As long as that son is not married here or anywhere else. It should take 6 months to a year, (I think).
Largely outside, but if there's green on a potato, it is sprouting, and is no longer safe to eat.