Hows it the biggest change to the industry in a century...when literally 25 years ago the MLS was not on the internet, and thus commissions not easily discernible from going to an online MLS.Literally we are just going back to something that existed in the industry not that long ago.

Join local meetings, attend real estate seminars and workshops, participate in online communities, and network with local real estate agents.

What are good strategies or online calculators to help make rehab estimates? 

Is the courthouse the the only solution, or are the records readily available online?

In some counties their online website will show the loan amount and date on the Deed of Trust.

I constantly hear people online (Social media) talking about getting an FHA loan and house hacking a 1-4 Unit property.

WArning:  You are asking legal questions in a forum online. 

It must be tiresome to have people call your bluff on your bs numbers day in and day out.Also, they use bandit signs and CONSTANTLY are reaching out to investors (unsolicited) online to get newbies.Why?

A very few online.#2. 

It's important to know and consider the max rent potential, cost of rehab, and municipal requirements (rent control, registrations, inspections).