I don't know how large your condo complex is, but for condos of 50 or more units, it would be a challenge to get every owner to get to it, and properly clean the vents if it was discovered  vents were never cleaned and it could be a safety hazard.I also had special assessments for new roofs, other building wide improvements at my rental condos. 

Because we are getting such an incredible deal on the property, we think we could sell it for about $75k more than what we bought it for and the next owner/investor will still have the potential of making a 6 figure profit if they sell it or gain 6 figures in equity if they keep it and update it.

I take the arbitrage loss as a trade off for emotional ease and I do it with my eyes wide open.If your eyes are open then there's absolutely nothing wrong with spending $226 per month to "buy emotional ease!"  

Incredible returns, no rehab needed, and you can buy/sell all over the country. 

That answer varies widely.

There's no perfect answer, because it will vary widely by location and the actual property. 16%-18% pre-tax profit (of sales price) is a pretty good rule of thumb.

Have incredibly strict criteria...that will solve your problem.

Start with some reading here: http://rapwp.oaklandnet.com/ Craigslist and Facebook are used widely here for rentals.

That caused a delay in the sells by companies like Country Wide. 

He is an incredibly bright guy who brings a lot of great analysis to the table.