Is sales tax registration required?

One way or another, you will want to sell within 3 years after moving out so you do not lose the tax free gain on sale (up to 250k tax free gains for single and 500k for married).

Potential for increase in rents and appreciation upto 3.5 to 4million in 5-6 years but not sure.Rents at 210k per year for 4 tenants. 50k per year total paid for common area maintenance by all the tenants - which includes property management fees, property tax, insurance, snow removal, other maintenance and misc stuff. 

Of course, if it's that easy of an answer I probably should have been able to find the answer on my own and should probably be charged my stupid/lazy tax for bothering him with it!

There are no income checks, DTI, taxes, or W2s involved.

LLCS are sometimes important to the states who won't let you homestead (get a tax break) a property in an LLC. 

The current rental income is $5,300/month, while our mortgage is $1,500/month, property tax is $600/month, property management costs $200/month, and maintenance expenses are currently unknown.We’ve utilized a HELOC from this property, amounting to $300,000, for renovating the basement and investing in a preconstruction condo and another property in a different city.

Even if you use a large amount of cash for the down payment, you can always do a cash out refinance in 12 months to pull out some of the cash "Tax Free".  

Section 1031 tax deferred exchange where the proceeds from the sale of the Property are used by a qualified intermediary to purchase like/kind property.

I would like to get this taken care of, because it's incredibly taxing financially when I have to carry these business expenses myself.Thanks,Nick