What does the tax ID indicate?

Is sales tax registration required?

HelloAny tax savvy people / cpas out there want to help me out. 

Ultimately this is not my burden and what ever happens does not affect me financially, but I still find myself up at 2am wanting to find a way to help her if I can, even if it's just providing her with a solution/way out.A little over a year ago, she took out a New Construction HML for her first Real Estate Investment project.

Some material or book that helps me understand which arrangement does what for asset protection and taxes would be great. 

And that's on top of the fixed expenses like taxes, insurance, water/sewer/garbage, etc. 

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".