That's why you definitely want to get rental income on this year's taxes, but it may not be in your best interest to quit your job until you no longer require it for qualification to get money from a bank.

Or are the qualifications different for an investment loan? 

Unless you have the down payment (probably 20%) and lender qualifications or the ability to make CASH offers, any offer you make will be contingent on selling your current residence.

I'd love to have suggestions on what might work well to get this done.3) Raise the qualification standards for renters.  

Who have a high bar for meeting their professional qualifications. 

There have been solid deals popping up this year, many have been triplex or 4-plex - those have different FHA qualifications related to the rents they bring in, so definitely run your numbers. 

Individual banks have the option to keep the loan in-house in which case the qualifications are whatever the bank sets. 

Period.This link will take you to the HUD rules, which includes a nice Q&A to walk through determining whether an animal meets the qualifications.

Are there specific income requirements for FHA loans, and can the income generated from renting out a multifamily property be considered as part of the qualification process?"

There is a wide spectrum of qualifications.