Usually 3-5 years.

And also: people are willing to pay a couple hundred bucks extra, too. 

First month's rent is usually due on move-in day.

I have some experience with HELOCs, but usually for smaller amounts and I am wondering if I can take out more than $100k in cash from the HELOC. 

You can always call their broker directly and complain if you are not receiving a response--that is essentially a way of reporting it to their boss and is usually very effective. 

The good news is that once you've landed them as a tenant, they are very good tenants, pay on time ( usually in arrears) and stay for a long time.State agencies, or state funded agencies are a little simpler.

They usually have the most extensive connections and can help you assemble the other pieces to your team. 

He wanted to house-hack his house by renting the extra rooms to his friends.

Some lenders offer this as well, but usually at 70% LTV and no greater. 10.

Again, its usually the real estate investor who is focused on anonymity and has a spearate management LLC without any legitimate reason who is in a position for their LLC to be pierced because they don't have an understanding of how their LLC's should be operated and are likely operated incorrectly.