You can do a 1031 exchange and use those funds towards another investment purchase (basically a tax deferment).

Usually in the form of special assessments or ever rising dues/property taxes.

I own my own business/LLC and am open to changing that structure for tax purposes, such as putting it under an S- or C-Corp if it would help with this situation.)I appreciate any and all thoughts on this matter as I can't seem to get out of my own head on this!

Prorated taxes (I understand this part)what other items that i should see on my closing bill?

For our customers, they fall under our business license and tax.

So many nuances from property taxes, insurances, what does airdna or rabbit say, cost of internet, HOA, permit costs, local utilities, are you doing maintenance or is someone else.... 

They're like real estate taxes. 

Financing and tax related issues will force the other into becoming part of whatever you decide to do and you don't want to overcomplicate your marriage with financial decisions that both of you are not on board with wholeheartedly.That being said, there are other ways to invest in real estate that don't involve you moving or evening buying a home.

And should they still file taxes separately or can they file jointly?

Mortgage, taxes etc amount to 1200 and HOA is 200.