I suppose technically you could even do some live streaming walk through feed.Looking to the intentions of the two types of loan investing, making the loan or buying an existing one, different variations of skill sets will develop.

There are a lot of variations across country.

Its like playing with real stocks with fake money. its a great way to practice. first for ARV- be careful using just price/sqft for valuations. it is almost ALWAYS more accurate to use comparable property sale prices rather than their price per sqft. and getting a good idea in your head for why their sale prices are higher or lower than the neighborhood average and sort of adjusting in your head for it. make sure that comparable property has less than a 20% up  or down variation in square foot, that it is a like style house ( ranch comps for a ranch, two story comps for a two story) , Make sure you are only using above sqft and above sqft as comps when you are looking for properties with similar sqft. if your house is a 2000 sqft ranch you will get a lot more for it than a 1000 sqft house with a 1000 sqft basement. this is very important.

Too many variations on the wholesaling method. 

There's a lot of variation within that and the long-term outlook for each neighborhood is not the same.It's not uncommon to find 100 year old houses in E, S and W San Antonio, which may be good for you if that means more demand for property inspections - I'd be interested to hear your perspective.San Antonio has a unique identity with the Missions and a strong Latin culture.

Its very thorough, but like most systems, works best for the middle of the range of PHA sizes and extremes in rental variation, as the system doesn't work well in places where there is very limited data (many rural PHAs), markets with rapidly rising/falling rental prices (SF for example), or places that have complex neighborhood divisions and wide range of rental cost within their jurisdiction (generally big cities). 

With all the design options that are available, and the wide variation of costs associated with all the different products and materials that can be used to complete a rehab, it is not reasonable to expect an accurate repair estimate without knowing exactly what a particular rehabber thinks must be done to make the house market ready; including product quality and grade.

I have two rentals and look forward to someday having 8-12% vacancy instead of large variation between 0,50 or 100%.I liked this line "It seems that having more properties is less risky than having fewer properties."

Of course there is more than that, and each lender will have their own variation on how they do these. 

Does this mean that you bought a house for - I'm making up numbers here - 200k, and the house appreciated to 300k in a 5 year period, and you did some variation of this multiple times?