you seem to be completely dicounting power usage and price. A 'home rig' may cost $0.09-0.19/kWh while a hosted rig at a data center will cost $0.03-0.09/kWh. a few dollars a day per rig, plus shared AC costs, means that hosting a 100 units on cheap power provides enough savings for all your above gripes (rental, techguy, etc)
I know that by paying less than 10c/kWh where I am, that it gives me a decent leg up over much of the USA's home miners, because the power usage will become more important than the hashrate very soon
Have you ever operated a commercial data center? I have, they cost a lot to run, and it varies from location to location, you can't generalize and say data center electricity is $0.03-0.09/kWh. for every watt of mining power, you use a watt of aircon/lights etc. Data center racks are some of the most expensive real estate on the planet per sq. ft.
http://www.electronics-cooling.com/2007/02/in-the-data-center-power-and-cooling-costs-more-than-the-it-equipment-it-supports/