Yes, you'll totally spend 10% just maintaining it then you'll have enough big ticket items to get you into that 2-3k (or more) each year.Tenants that live 600/mo or less will not all treat your property well.

Honestly though, if you're in VC and can get into some early rounds of funding on some decent projects you'll make a whole lot more money than buying 4 plexs ever will.

Also, could anyone recommend a well rounded real estate broker in bucks county pennsvania that work with flips? 

Already bought my ticket.  

Also related question: When an offer gets accepted, would you always suggest bringing in a professional inspector to look for high ticket items like plumbing, electricity, gas, etc?

Finally I rounded all numbers to the nearest $100.

Make sure you have a copy of the agreement between yourself and the landlord.You could probably get away with not paying rent until the bank gets involved, lol, although I don't advise that.

I am looking for a market for SFRs within 3 hours of Austin / Round Rock where the price to entry is 90k-120k for B Class areas.

Actually my first choice was going to be economics for the exact reasons you've mentioned, it seems to be well-rounded and a great foundation.

This is typically around 10% and accounts for big ticket items, such as new roof, HVAC, etc. 5% for reserves is probably a little light also, but I like to think worse case scenario to ensure my properties cash flow.Typically people use loans for down payments simply because they don't have the capital up front to get into deals.