If you screen your tenants effectively and set expectations before signing the lease you will minimize many of the problems you mentioned not wanting to deal with.When they do arise you can either refer back to lease/expectations or evict.

There are investors that do this kind of thing with HUD homes as well.They sign paperwork at closing that they are occupying the property.Another component of this is fraud to a lender on a loan if you say you will be living there.The reason is lenders give certain rates to owner occupants because statistically you will fight much harder to keep a place you live in.If it's just a bad investment it is easier to walk away hence a higher rate and more down.This property from what you said is 2,400 X 12 = 28,800By half is 144,000 at a 10 cap based on 50% costs.The carpet and paint the bank put lipstick on it it appeal to a home buyer living in one unit and driving the price up.On a quad typically you could expect about 8,000 for the siding,4,000 for the roof,6,000 for 4 outside A/C units,if interior bathrooms and kitchens are outdated about 4,500 by 4 units is 18,000,then water heater and heater about another 6,000 total.So conservatively I have about 42,000 in immediate CAPEX.Every areas cost is different so I am just throwing mine out there.Now the other you say 20 quads total is what you need to worry about.If there are a bunch of short sales and foreclosures from vintage 2004,2005 loans then the new purchaser with a cash offer or a small debt service will rent below market to fill quickly and turn more or the same monthly cash as you.So you starting out at 600 rent monthly might go to 550 or 525 in your development.I have seen this happen.I have also seen even if your building is well kept quality tenants do not want to live next to the other buildings where landlords put in suspect tenants to fill up.Also some landlords with high debt service will drop rent instead of repair to keep tenants so they won't spend tens of thousands out of pocket to rehab.

I found an excellent tenant who was more interested in "character" than quality."

the tile holding up has a lot to do with the way the structure is built and the quality and specifically the thickness of your existing sub floor. if your subfloor is less than 1 1/8" thick i would look at options other than tile.

You have to screen them all separately.

He actually hires a PM to find potential tenants who are qualified, then does his own second tier screening of the final list of tenants and the PM gets half of first months rent.

The first ones to arrive get to be first at filling out an app.I do the screening in order of receipt.

This question lumps the quality and applicability of all degrees together.

Some reading on this subject:http://www.biggerpockets.com/forms/TenantScreeningHowtoVerifyInfo.pdfhttp://www.biggerpockets.com/forms/TenantScreeningPolicy.pdfhttp://www.biggerpockets.com/tenant-screening.htmlhttp://www.biggerpockets.com/forums/52/topics/74397-online-tenant-screening-with-smartmovehttp://www.biggerpockets.com/forums/92/topics/63767-do-you-guys-use-bp-smart-move-for-tenant-screening-http://www.biggerpockets.com/forums/52/topics/31452-what-is-the-best-tenant-screening-service-http://www.biggerpockets.com/forums/52/topics/61919-which-tenant-screening-service-do-you-use-http://www.biggerpockets.com/forums/52/topics/44614--tenant-screening-credit-checks-for-landlords-http://www.biggerpockets.com/forums/52/topics/16482-tenant-screening-serviceshttp://www.biggerpockets.com/forums/52/topics/22967-best-tenant-screening-siteshttp://www.biggerpockets.com/forums/52/topics/73710-online-tenant-screeninghttp://www.biggerpockets.com/forums/52/topics/70649-screening-tenantshttp://www.biggerpockets.com/forums/92/topics/60985-opinions-of-ntn-for-tenant-credit-report-etc-http://www.biggerpockets.com/forums/52/topics/43049-credit-report-screening-service

Landlord has very quality products and information.