I search this site: http://www.oscn.net/dockets/Search.aspx to find evictions (in Oklahoma it's called a Forcible Entry and Detainer) and criminal history.  

Then I went on county website and looked up owner's unlawful detainers (?)

Bought a Foreclosure in my single member LLC and I need to file an unlawful detainer eviction. 

The termination notice, called a Three-Day Notice to Pay Rent or Quit, gives the tenant three days to pay rent or move out.If you haven’t followed the rules, and the tenant doesn’t pay or move within the specified three days, you’ll have to file an eviction lawsuit (also called an unlawful detainer).

All communication in writing so you can present it to a judge at an Unlawful Detainer hearing.3)After raising the rent, I am 100% sure that tenant will begin to argue and make claims of the legality of raising the large amount at one time.How would you respond to baseless claims of the legality of the rent increase?

I recently had the same issue with a tenant who didn’t pay any late fees or NSF fees so I contacted one of my attorneys specializing in forcible entry detainer law,  who advised me that we can’t collect any fees out of rental payment. 

If I go to court and file the unlawful detainer, pay the fees due (not cheap in CA), and serve the tenant and then he decides to pay his rent - will I be able to continue the eviction, or do I have to stop, lose the fees I paid and do it all over again next month?

That's a lot of work and unless your brother-in-law lives next door, YOU have a lot to do.2015 had a nasty unlawful detainer with severe damages. 

My attorney says they are having success with evictions from lease violations outside of non payments and with unlawful detainers.

So know the law, Know your lease and underline it and give a copy back to them, With that said.Yes charge them the $50.00 late rent fee. and If they don't pay you tell them you'll file unlawful detainer eviction action for non-payment of rent , you have no guarantee how they will leave the apartment.