It's about 1.5 to 2 years to complete the process. Strongly suggest you spend more time in person.
Additionally others recommend going the spouse visa process instead. Cue crazy cat with the comparisons.
Any traffic fines under 500 dollars does not have to be mentioned unless it's drug or alcohol related. Ask your friend if it shows up on driving record. Sounds like it was handled in traffic court.
The post mark is the day you hand it off to the clerk at the window at post office. Obviously send certified mail return receipt. Retain slip showing post mark.
Better file and have shipment postmarked before April 1st or you will have to pay higher fees. Also effective April 1st separate payments are required for 485, 765, 131.
I don't think it's a rolling year. Each trip is treated separately but the total days outside the US factors when applying for citizenship. As I understand it any time spent longer than a year causes concern when coming back to the US. Also you mentioned you have a 2 year card so something to keep in mind because you don't want to miss any potential interview for removing your condition
There is no hard and fast answers. Just remember the green card is for living and working in the US. With a travel pattern you have described an argument could be made by cbp that you have failed to establish the USA as your residence. Are you planning to apply for citizenship?
To my understanding the employment authorization is not renewed, you have to apply and be approved for adjustment of status. Then once approved you get permanent resident card and that overrides the eac card
It shouldn't be a problem. As long as the form is properly completed. I believe the form expires after 90 days from signing. I did this renewing my kids passport with no issues
Officially not longer than a year but try to keep it under 6 months. Otherwise you have to file for reentry permit. Also prolonged absence delays your ability to file for citizenship