Seems that inventory is very low, property prices and interest rates are very high.  

The reality is that low supply of single family properties will keep a high floor for prices.  

Your concern is a good one, buying in this market at high rates = high payments and you may not cashflow if you were to repeat the process.However, 2 considerations. (1) By not doing it you don't have 800-1000 in your pocket, so although the payment on the new place might be higher than in a normal market you've got extra funds to cover it.(2) Your new rate is not forever, perhaps in this high rate market, it's as you say, best case you're breaking even if you repeat this process.

There is a vetting process for members, which helps to keep the quality high, but a downside is that it's not as big as other groups. 

She threatened me that if I don’t give her a full refund she will definitely give me a bad review.

The two downsides to syndications are the high minimum investment and the difficulty in finding good sponsors and deals, but you can solve for both by joining a passive real estate investment club.

I would avoid spreadsheets, since there's definitely a "too many cooks in the kitchen" problem with that approach. 

A bit high, but hey you can try and deal with all the headaches, see if it's worth it.

There are some "lenders" out there who "do" incredibly high leverage or 100% financing, but be wary of these as they often try to renegotiate terms before closing/run out of capital/go bankrupt.

I no longer qualified for traditional financing because I already own many rental properties and my DTI was high for the bank, so I purchased these in a business entity with a trusted private investor and was able to refi the 1st property/sell the 2nd property to pay back my investor and ultimately keep the better property for zero money down.