1/2 first month's rent seems normal. 

Back out your wholesale feeFlippers normally want properties at 70% of ARV less repairs So if the ARV based on accurate comps is 100k and it needs 10k in work.....and you'd like to make 2k....Your offer would be $58,000. 

Additionally this is just a theory I have but I also believe that there are times when bank liquidity issues are also a factor to when they will accept lower than normal bid prices, and low foreclosure pricing.

This is very normal and even though it leaks it potentially is still fine.

For example, the "normal" property configuration in some neighborhoods are a 1-bedroom or a 2-bedroom. 

. - Considering the money involved, is it normal not to hear from your realtor and for things to take so long?

Normally a $1400/mo rent will more than support a $100k house, in my area anyway.  

I AirBnB a couple of my spots and as I said in a previous post, if you have a decent location you are getting a nice to huge premium using AirBnB over normal rents.The long term forecast is much less rosy as city's look to extort more taxes and fees, the hotel lobby mobilizes against AirBnB, and the market becomes saturated thus lowering the margins.My advice is to ride the gravey train while you can and if your buying mainly to AirBnB look for additional exit strategys

-What is the normal amortization length for investor financed SFHs?

I am normally not the color selector on our projects, as you can tell.