That LLC then limits the liability of the IRA and you personally in ways that a property directly held in an IRA will not.

You can request a security deposit to cover you for such eventualities, in some states there is no maximum, in some states you have to inform the tenant/s where/how the deposit is being held.

Example: Gross Loan Amount: $120,000.00Rehab Hold Back: $60,000.00 (We release this as work is completed, no draw fee and interest is only paid on money advanced, not held back)Loan amount at closing: $60,000Rate: 10% Origination: 2.5% Doc Fee: $600.00 Term: 9 months 

An implication of this is that if I held a property for 10 years and accumulated, say, $100,000 in cash flow over that time, there's no way that I'd actually have $100,000 in cash in a bank account because I'd have put it in an interest-bearing account long before then.

If you are new, you may be held to their standard loans i.e. 15 year term 5 year apr with a seasoning period, but if you are more of a seasoned investor and show a history, they may be more likely to be lenient with their terms. 

We're entering year 11 and $270K depreciation has already been takenand the original basis of the 1031 plus improvements might be $50K.The property has always been held and managed by one individualso Is there anyway to bring in a partner into a LLC or other vehiclethat can avoid triggering the capital gains due to the IRS and Utah?

Why are you differentiating "starting out"... as if it makes any difference...which it doesn't.Have you ever played poker? 

The replacement properties are also held in joint title as required. 

But in the Boston market, and especially in such neighborhoods as Cambridge, Charlestown, Southie, Somerville, and many others that have had multi-family buildings held by families for many decades, this is normal. 

They say any untaxed capital gains invested (I assume they mean 1031 exchanges) in to these areas will have “zero taxes on any capital gains” if held for a minimum of 10 years.