don't make that assumption but let them make that decision.

Every market is different, you should probably use the Bigger Pockets calculator to run your local assumptions through to see. 

This is a huge assumption.

What are the assumptions that are being factored in - namely occupancy rate and rent per square foot per unit type - and how do they compare to the local market?

Have the seller check with his lender and see if they allow loan assumption or not. 

I am making the assumption you, the reader, have already done their homework in terms of what a syndication is, and the benefits of it.The first step you should take when considering syndications is decide what your time horizon is, the market you want to hit, and find out what your investment return goals are.

Taxes will be ~$6500, so that leaves me with 46.5k in pocket, free and clear.I cash flow--after taxes, mortgage, maintenance, everything--about 380/month with the property, so it'd take me 10.2 years to make 46.5k in profit assuming (assuming rent doesn't increase or costs go up--big assumption, I know, but I can only work with the data I have now). 

As always, it depends on your goals, but if part of your goals is cash flow, you do a similar analysis with your own assumptions.

Just like any assumptions of the future returns of the stock market are just that; assumptions. 

Not so good lenders will assume the appraiser will get the job done timely, which is never a good assumption.