In addition, what will happen to the tax write off since both properties are paid off? 

Yes can definitely turn your current primary into a rental and purchase a primary in FL where your employment is moving you to .

If the report indicates a failing septic system, this triggers additional county oversight.

I’ve done my best to research the process but wanted to get additional guidance.

Alongisde that, it will be important to have stable employment, because your job is what helps you qualify.  

@Abiy Tedla I have mostly gone with white cabinets with black hardware on the same as is the market trend currentlyPersonally, I'm a fan of staining cabinets more so than painting since it lasts a lot longer and is more durable (plus I think it looks nicer than painted cabinets too) Additionally, using stainless steel appliances and under-mount sinks definitely adds to the oomph factor of the property even though they aren't much more expensive than their counterparts

In addition to the other replies, if you are on septic I would not install one.  

Hey Pratik, I'm personally not a fan of new construction because there is no value-add. It's

Do you have enough money left over from your home sale to finance the 4plex as an investment property (additional 10-15% downpayment.) and then still have enough left over for a downpayment on a new home?

The board is new voting on covering the additional 25% next year.