@Account Closed , I hope you dont mind me chiming in since you asked about Brian's deal, but hopefully it will give you another perspective in addition to his....
I'm currently working on a multifamily group purchase, and will tell you how your questions apply to my situation. I'm also evaluating someone else's deal this week that I may put some IRA money into as a passive investor, and their deal is structured the same way, so the info below will apply to both.
Interest rate: We will not have a preferred rate. Our investors will share equally in the return of the property, both in monthly cash flow as well as any capital gains at sale or proceeds from a refinance. This return is after a subordinate interest on cash flow and gains that will go to the sponsor, but only after all investors have gotten 100% of their initial investment back. The sponsor will begin getting the additional returns with the first distributions, but if investors have not gotten their initial investment back at reversion, any sponsor returns on those gains don't kick in until they do. There are also deals out there that grant additional equity up front for the sponsor. For example, an investor puts up $100,000 and the deal sponsor gets a percentage right away, regardless of performance. I don't like that setup because it gives money to the sponsor before they've earned it. A sponsor has to be careful with that structure because it can be treated as earned income immediately and would be a huge tax hit. If the sponsor was granted 20% equity in the $100k above, he'd show $20,000 in earned income.
Cash Flow Distribution: This really depends on the deal. On the passive deal I'm looking at, it has a lot of rehab, so there likely won't be much of a return the first 8-12 months, and this is clearly spelled out in the PPM. I know many people that invested in stabilized properties that began getting returns from day one, although distributions are generally made each quarter. On the amount, it seems to depend on the sponsor. I've seen some that distribute any money above a set amount in their operating account (say one months expenses + one months debt service), and some that kept a bigger cushion in the property's account.
Forgive me if all this is too basic, I just thought you might like to hear the perspective of a much smaller scale person than Brian!