After i signed the purchase agreement, it was like pulling-teeth trying to get confirmations from them, or any type of communication. 

This will show you all of the Bigger Pockets members in that area who you can potentially connect and communicate with. 

Or is there a more effective way?

Is there a simple and effective way to analyze a property, or is calculating the cap rate, 1% rule, 50% rule etc, cash on cash, NOI, all necessary?

@Shayla Fletcher I check all properties at http://maps.lsuagcenter.com/floodmaps/ If the flood hazard areas show in blue, (or sometimes grey on old black/white maps) that is the effective map that is used to determine flood insurance rates and whether or not flood insurance is required by lenders. 

Networking and cold calling are the most effective for lead gen.

I do have a couple of recommendations for you though; Ask the listing agent ' Is there anything aside from price that the seller would prefer to have in an offer,' such as Specific closing date, or a lease back so that they may find a replacement property, etc....I have found this to be a very effective way to extract some of the seller motivation.

Multiple marketing messages in one mail piece would increase effectiveness.  

If they are good people, pay well, communicate well and screw up due to life events or unfortunate circumstances, I may even cut them a break and allow them to dig themselves out of a situation beyond what is agreed in writing.I want win-win deals. 

I don't think my current method of paying my handyman an $85 trip charge is cost effective.