Questions About Mailer Settings - Suggested G Suite settings?
Mailer Batch Limit: If I set this to 250 - Everytime the cron is run - up to 250 emails should be sent until entire mailing list is emailed - correct?


Yes


  Mailer Throttle Time: If I set this to 10,000,000 - an email will be sent every 10 seconds correct? That also means the mailer will be working until all the emails are sent.


No. It will carry on sending until the Mailer Batch limit is reached, or if no Mailer Batch limit is set, all emails have been delivered. 


  Mailer Job Size: I have no clue what this means but since our list is under 1000 - I take it it does not apply to us.


This allows you to split the mail into smaller chunks that can be run in parallel.


  Mailer Cron Job Limit: If I have it set to 2 jobs, and a third job is scheduled to run while the other two are running, will it just queue that third job until one of the other jobs ends?


Yes, though that isn't really the point in this setting. You commonly see it used in conjunction with MailerJob size. Lets say you have a mailing that is to be sent to 100,000 addresses. You could split it into 100 Jobs of 1,000 and run 2 or more jobs in parallel if you like. Depending on what the limiting factor is, this may increase the rate at which you can send out mail. Which may or may not be a good thing for you :)


  Also - Is there any reason why I shouldn't use GSuite as my CiviMail provider?


Given the volume of email you mentioned, I am guessing you will be ok. There is nothing in the terms or service that would suggest you shouldn't be using it for your use case: https://support.google.com/a/answer/2956491?hl=en. As long as it can pass back bounce messages to CiviCRM (important if you do not want to be labelled as a spammer) you will probably be fine. Worth trying it out and reporting back at least.