If you have her deposit, and nothing's damaged, make sure the lease doesn't contain a holdover provision regardless of who the owner is - and if not, then her lease is complete and she can go on her happy way. 

I’m concerned about potential future losses (both income and property damage) and want neighbor tenant evicted.

If yes, what was the outcome   Does the tenant owe any monies for outstanding rent, damages, utilities etc?  

In Canada we aren't allowed legally to take a deposit for potential damages, instead we take first and last months rent ahead of every lease . 

After leading us on for nearly 8 months, she finally informed us that the bank rejected her financing because the house is wooden and has a greater risk of being damaged by the tropical weather.Recently we were presented a cash offer of 75k and the house was appraised at 112k in November 2017.

So if someone has a leak upstairs and your unit gets damaged, it’s your insurance that responds and not theirs.Let me know if I can help with the quoting process.

Also, even if he manages to lien the house, he still needs to go through a law suit before the lien can cause us any damage?

It looks like hardwood floors, looks great and I've never had any damaged to date.

You'll essentially be a holdover tenant if you don't leave on the previously agreed upon date, so the reality is you could get into legal trouble because they could pursue an eviction and other monetary damages against you.

IF (big IF) you do get a letter or call from an attorney, let them know the bill is owed by the tenant, and if pushed, you intend to counter sue for excessive damages and report the drug paraphernalia/evidence of use to the local drug enforcement agency.We are talking about a small-claims court issue at best, and personally (I am not an attorney) I would keep all timelines, damages, photos, expenses and communications in a file.