Do I need a banking resolution?

You can be seriously fined if your tenant disputes a credit inquiry and you can't produce the SIGNED authorization on the Rental Application within the 25 month period.

The greater risk is being sued over a security deposit dispute which an LLC or umbrella policy will do nothing to protect.There's much more to say but you'll have to educate yourself.

Did you find resolution to it?

The vast majority of lawsuits against Landlords are for wrongful eviction, security deposit disputes, and Fair Housing Violations.

If you have anything negative on your credit report pay it in full or settle it for 40 cents on the dollar roughly and go to Google and type in "Transunion Dispute, Experian Dispute and Equifax Dispute" and go to all three pages.

Should be a simple resolution, but you might want to consult with an attorney, this is probably a simple boiler plate form for them and should not cost a lot of $$, however they might have some input on to questions that might need to be decided on what and how to add.

We have a SFH on a cul-de-sac, so the lots at the end aren't straight rectangles. The neighbor is claiming that a small section of our lot is his. (It's not, as clearly shown even on Google maps)  Our mutual backyard ...

How i can resolve this dispute?

For such a small amount, your title company may also allow you to close escrow with the amount in dispute plus a buffer withheld until the lien is removed and you agreeing to defend and indemnify the title company for its losses if the claimant actually attempts to perfect the lien.