I'm assuming your due diligence took at least a week, a 3 week closing would totally have been realistic assuming you're well qualified etc.Two weeks, when you factor in that you're posting on internet forums instead of actually getting things going, meaning really it's 8 or 10 days from a lender's perspective, is not at all realistic. 

As far as the closing cost and rehab numbers honestly a broad guess.

SFH was vacant for 6 monthsThe owners lived in New Jersey / out of town owners YESResearch and learning all you can about the property is very easy to do with the internet, but it does take a little bit of time and legwork + I was learning along the way.

To date I have been running everything out of a fairly sophisticated excel sheet... but I know there is a better way.It doesn't take many searches to see the internet really likes to push Quickbooks. 

I know there are agents that think I'm foolish for not using it, but I simply view my relationship with clients differently.2) if you're looking in a very broad area, there are absolutely agents out there that will be fine with you using multiple agents ...

When I purchased, my mortgage was around $1,650 and the HOA fee was $515/month including cable/internet.

Obviously an incredibly broad question (dependent on market, economy, demographics, neighborhood etc), but has anybody seen this statistic anywhere or crunched the numbers to get a rough figure? 

Is it possible to find a multifamily property on Trulia and buy it over the phone/ internet without getting screwed?

I've been scouring the internet, watching YouTube videos and pod casts.

Each type of asset has different requirements especially commercial vs residential but overall the process looks like this for commercial or multi family:Check with the city or county to determine what is required for all approvals including site plan and building permits, proffers, water/sewer tap fees, bonding requirements, inspections and CO process and time frame for all approvals.You also need to check with the utility companies and get an idea of availability and cost estimates from them for water, sewer, power, gas, cable, installation and connection requirements, tap fees, hookup charges, transformer location and relocation, power line and power pole relocation issues.Check to see if you have to install any manholes,fire hydrants, curb, gutter, sidewalks, street signs, street lighting any specific street design or access requirements,.Check DOT requirements for access, stop lights and permits, traffic studiesDWQ requirements for permits, permit fees, time framesThis is a broad overview of the process and your civil engineer can handle all of this but it's good for you to know exactly what's required.Residential is much easier but similar considerations.