My main concern is impact noice and airborne noise across floors.my current plan is to lay vinyl planks, and a good quality underlayerment over the existing wooden flooring in all the upper floors.

But I've been receiving BP info for the longest, heard about it again on YouTube and decided to be more engaging as you as all might have the expertise to assist... 

Reach out to the agent that represented the buying party (they are now the current owners) with an offer to present to their past client.A few reasons this works 1) the buyer's agent info is easily accessible and most respond to text within a few minutes. 2) The buyer's agent is a warm entry point and the offer is typically given more serious consideration. 3) The buyer's agent is given an excuse to re-engage a past client so there's a very high likelihood your offer gets into the right hands- this is especially valuable when the buying entity is obscured via LLCs which makes finding reliable phone numbers more difficult.

Even if you plan to do #2, keep aggressively looking at deals and stay engaged. 

New sub-floor and laminate plank flooring inside.

I don't want to give reasons that are too specific and set myself up for engaging in dialogue.

My concern is that the house may not appraise for our offer price and my question is if it's atypical for the buyer to engage in the process of "cleaning" and preparing the house in preparation for a lender's appraisal.

Anything that requires value-add will require some engagment regardless of your options.

HAVE FUN and stay CONSISTENTLY ENGAGED.  

With a WY LLC could you engage in the following real estate areas wholesaling, lending for commercial and/or residential business opportunities, short-term and long-term rentals?