He is now selling the property and the new buyer says she cannot find an insurance company that will issue her a policy because it doesn't have central heat/air.

Maybe you could contact a local STR management company and work for them for free to get some idea of what is to manage a STR.

Can anyone give me any input on any or all of these companies?

Both the agent and insurance company.

Everything should still be done through a title company and you own the home - so you can sell it at anytime and keep any monies if greater than what you have left on the loan

If you have the cash, proof of funds is easy: Screenshot a bank balance or provide a recent bank statement.If you have a legitimate hard money lender who has underwritten the deal and confirmed you have the down payment and cash to close, they should be able to provide you a letter stating exactly that.If you have neither, then you have no business making an offer in bad faith and trying to tie up the seller's property.Also (and this is crucial and a common rookie mistake) - Don't send a "cash" offer to the title company and then neglect to tell them about your hard money lender.

I have a question regarding the address for an LLC my wife and I just launched to serve as the property management company of our current and future homes.We are preparing to rent our current home to our first tenant and move into a new home.

@Season Price Usually, when we are searching for lenders, title companies, plumbers, etc. it's best to ask other investors in your market who they use.

Do property management companies need a real estate license? 

@Ash BisariaRecommend exploring as many sources as possible to get referrals AND cross-reference them to get as much accurate information as possible.Check out NARPM.com, BP’s Property Manager Finder (BiggerPockets: The Real Estate Investing Social Network), etc.Also, encourage you to learn from the mistakes of others - by reading posts here on BiggerPockets about owners not having their expectations met by their current Property Management Company.