I personally understand...Just wanted to see where all the people are that are saying they can BRRR a property with $0 invested & still cash flow.

Hi guysI see a lot of videos of people doing mid term, but i have hard time to understand something . they said the x4 their monthly rent.When Im looking on furnish finder , i see the rents jumping by $500 not more.example: From $2000 to $2500-2600.So how it make sense to doing x3 and x4. because then it will be $6000-8000 per month... can you elaborate and explain me ?

The point is to make sure to ask that question and understand how it would effect you going forward. 

As far as I understand, banks usually start the bidding at the judgement amount owed. 

If you are treating your STR as a business, I have a hard time understanding why more people don't allow this.

Ensure you thoroughly understand the terms and conditions of any HELOC you consider, as investment properties often have many different requirements than primary residences.Don't forget to look at other funding options and compare them against a HELOC. 

Initially, when I started in real estate I could never understand why a seller would sell a property for nothing down or other advantageous terms to an investor.

That is super odd.

My understanding is that military can receive an extension of the "must live in the home 2 out of 5 years" to 10 years.How does this work for taxes??

Having a simple written agreement of loan terms and responsibilities of the two parties is always nice and it doesn't have to be from an attorney just something clear that you both understand and agree to with a signature.