I think you are getting some great advice in here.I agree with most of what @Rob Belandand @Ray H. have said.Won't regurgitate all the same stuff so will just add a few details and places where I have different thoughts.Yes you can ask for leases with proper notice, or ask for formal TAW agreements to be signed and either of those can include a rent increase if you are inclined to do that.One thing to keep in mind for notice is that it is 1 month or 30 days, whichever is longer.  

If you think that the agent told the seller to try to get out of the contract so she could list it I would put in a formal complaint.If you want the deal I would (or have your attorney) get in touch with her Broker and inform him/her that you already have a contract on the property and this agent relisted it and presumably has a new buyer for it.  

The current owner didn't use a formal walk through check list, but said he looked for clean when tenants vacated. 

The current owner didn't use a formal walk through check list, but said he looked for clean when tenants vacated. 

Or formal training. 

Because, closing costs imply a formal closing with a closing attorney.

It's just the casual conversation, networking and deal making part with no formal agenda, speaker or sales. 

Advantages are that its typically simpler and can be faster than a formal probate, however it still requires noticing DHCS (Medi-Cal) and other creditors, so from a practical standpoint will require six (6) month for your seller to get thru court.

It's a valuable asset you will have the rest of your life.A formal education will also teach you how to think differently. 

How do you form all these relationships?