Surely your 1031 intermediary can advise you?

Typically, 1031s are handled by Qualified Intermediaries (QIs).

Where would I look for a reputable intermediary for a 1031 exchange?

Instead of you taking title to the new property immediately your QI (the qualified intermediary who performs the 1031 for you) takes title to the new property and holds it while it is improved (maximum of 180 days). 

You can start the new property and reverse 1031 into them when you sell the other properties.You can do an Imrpovement exchange and sell the properties first and then exchange into the "To be Built" property but the timelines of 45 day and 180 days will apply from the first sale so you need to be a able to complete the sale of the properties and construction of the new property within that time frame.Best thing to do is speak with your account or a qualified intermediary. 

I always use an intermediary that services notes, in Utah the the place I use is called escrow specialists.

I will keep you in mind when I'm ready to perform a 1031 as I can see you are intermediary for 1031 transactions!

Would it have been fair for Maverick to disclose during the web presentation that they were not a turnkey provider, rather a third party intermediary / marketer bringing together investors, sellers and PMs?

I very much like checkbook control and wouldn't do it any other way as it allows me to control the funds without an uneeded intermediary.

Intermediary broker vehemently defends this stand of the seller.