You can legally put the property into your LLC, however if your property is not registered in the same state, you will not be able to do any legal action on its behalf in that state (file for an eviction, contest a code enforcement action, etc...).You can either register your foreign company in that state or you can open a new LLC in that state.

How does the previous owner contest the tax sale and how will I be able to recover the money I have invested?

From a Keynesian Beauty Contest view, I'd rank them 1,3,4/5/2 from least to most risky, keeping in mind that #3 is passive, until it isn't and that there are too many variables to accurate differentiate between #2,4,&5.

He may be talking about trying to remove it from his credit report, through the old “contesting it”.

He heard of a contest in the USA that he couldnt afford the trip back from if they lost. 

A six-year-old misdemeanor presents no risk to the property, the other tenants, the Landlord, or the Property Manager.I suppose you could contest it and ask them to justify their decision but do you really want to rent from a Property Manager that doesn't even know what constitutes a justifiable rejection?

Can this be contested?

Boosting a post just gets additional views and is best for sharing an article, information, or promoting a contest/giveaway. 

Thought I would share a success story regarding getting an appraised value adjusted with success.  With the amount of homes we sell every year, occasionally we run across a situation where the appraised valued comes i...

The big news here is that a class action law suit is going forward against the City of Bedford in the Northern District of Ohio contesting "all homeowners who were forced to endure government searches as a precondition to the sale of their homes are entitled to demand refunds of illegal “Point of Sale” inspection fees".A similar suit has already been adjudicated in the Southern District Courts in favor of prohibiting the practice as a sale requirement.41 communities in Northeast Ohio require some type of POS for title transfer which I'm sure is a source of income the cities don't want to see disappear.