2nd and 3rd options are same and 4th option returns 2016. None of the above should be an option....

Hi Glenn,
If it says the database has been fully recovered/restored, you pretty much have no options to revert at this point. You have to basically restart the restore process...

Refer below links for getting an idea....
https://dba.stackexchange.com/questions/37583/moving-sql-server-to-different-domain
https://blogs.technet.microsoft.com/fort_sql/2011/04/02/changing-domains-on-a-sql-server/

After moving to new server, Did you made sure required network protocols are open(Enabled) and firewall settings are good?

Thomas Russ has posted a creative way of dealing with multiple BAGs sometime in 2016. Just wanted to make sure, you read this article before drawing any conclusions...
https://sqljudo.wordpress.com/2016/07/25/a-group-of-basic-availability-groups/

you can script out existing logins with hashed pwds using sp_helprevlogin. or below script should be helpful...
SELECT 'IF(SUSER_ID('+QUOTENAME(SP.name,'''')+') IS NULL)BEGIN CREATE LOGIN '+QUOTENAME(SP.name)+
   CASE WHEN SP.type_desc...

Well, You don't have to either upgrade your 2014 publisher(Prod) or downgrade 2016 subscriber(your AWS Instance). All you need is SSMS 2016 or higher(Just client tool). FYI you can download...

Looks like you are setting up subscription(s) using SSMS. Try using T-SQL script(s)  or create subscriber(s) using SSMS 2016 or higher.

Also, Since you are getting this error when you are trying to access SQL error logs from your SSMS. Just wanted to make sure, did you try to open SQL...

I don't have POSH script handy, but Powershell is the way to go IMO.

Application logs should have more details on why it's failing. What are the findings from event viewer? Also check "SQLAGENT.OUT" file for hints...

That occurs when "CHECK for Object existence" is turned ON in your SSMS 2016.
Make sure that option is set to "FALSE" under tools->Options->SQL Server Object Explorer ->Scripting->Object Scripting options.