Also, the rate at which new properties are being snapped up suggests that there is quite a bit of interest among the investing public.   

For those of you that do an online application or furthermore just a simple "form" that is completed online, how do you go about acquiring and subsequently providing proof of obtaining such authorization without a signature?

Go to a new home community, sell it out, then turn around and become a realtor and pick up all the resales since you would know everyone in the community and hopefully they all know love and trust you.As you consider brokerages to actually join, look to see if they are public or not. 

It's easy to obtain, costs very little, and doesn't require extra, on-going effort to maintain.

Hello I am a current real estate investor/ new real estate agent and I obtained 2 properties with creative financing.

You can obtain one for a rental, and it may have a slightly better rate than some of the other options. 

It's easy to obtain, costs very little, and doesn't require extra, on-going effort to maintain.

If I purchase a property with cash, can I still obtain a mortgage later?

House hackers looking to buy close to public transportation has been a huge win.  

One thing I learned from a long career in public service is that it is better to underpromise and overdeliver than the other way around.