Or is it a good idea to have backups and always get multiple bids.

We work with multiple lenders that offer 65-80 LTV additional with Mezz financing.  

I did not hear back for 2 days and they I have to call to find out there was now multiple offers on the house.

I love the concept of having multiple passive/semi-passive income streams.

How to manage multiple properties across multiple states?  

Tell them "My business is based on referrals and my goal is to provide you with 10+ service so that when you close on your home you feel confident and excited to refer me to your closest family and friends"2) Then: when the transaction is at it's most emotionally charged (positive) state, say they just won out on a multiple offer, ask them for a referral.

There are multiple MLS boards in South Florida.  

I am connected with a wealth of investors and anticipate making multiple deals (4-6) over the next couple of months.

I am connected with a wealth of investors and anticipate making multiple deals (4-6) over the next couple of months.

I've found it much easier to manage one calendar per property and sync it out to the various vacation rental sites than maintaining multiple calendars across multiple sites.