I want to take a Heloc but always was scared of it...I want to open it just in case, sort of like if I lose my job, etc...1) Do I understand correctly, if I open a HELOC but do not borrow the money, then this I do not...

Your greatest tools when thinking about the location within a city are individuals operating on a daily basis within that market, such as Property Managers and Brokers. 

The vacancy of 5% is as bit low for my liking, but that's truly up to the individual.

We teach this all the time and I will always recommend it when done correctly.

The structure would be an Equity 506(c) The Ideas Already in place: -Brokers-Online websites such as equity funding platforms-Private Banking Firms-Relationships PPM document creator has with other investors-Forums-Companies that sell lists-Opt-in accredited investor databases-Firms that do the marketing with you (must be licensed)-FINRA broker-dealers-Individual securities brokers-Registered Investment Advisers-Private equity firms-"finders" for capital.

Is it possible to have the title of an investment property named as an LLC with 3 individuals as members with one of the members the sole mortgagor on the property?

Unless you are paying some ridiculous 5 figure sum to someone who is going to teach you “everything” (I dont recommend this btw) I would suggest that you evaluate what strengths you have, what skills you can bring to the table and offer those things to someone in your market.

When inquiring with the bank or credit union regarding their equity LOC product I would first ascertain how they allow the property be titled (individual, revocable trust) before even initiating an application. 

A friend and I who each own individual properties are looking to start purchasing property together.

If OP’s LLC satisfies the definition of “the insured” in the policy there is no need for an endorsement or a new policy. 50/50 individual owners to LLC where the individuals are 50/50, for no consideration other than the interest in the LLC ... this type of transfer meets that definition.