It seems a great HVAC guy is really hard to find and worth his weight in gold in Florida. 

So one could argue "lighter" turns are easier every year or two, versus, extensive turns after a few years. - How risky are student tenants?

It's true you get a tax deduction for your mortgage, but you also pay taxes on whatever else you decide to do with that money.I would list all of your known investment opportunities, what you think the after tax returns would be, and a risk level 1-5.If paying the mortgage is a clear standout on that list on a risk/reward basis, I would spread out the $60k over a period of time and apply it to principal.You might have other goals like cashflow or reducing risk which might weight towards paydown also.

. $400 for a 2-day rental of an 11-yard dumpster might seem high, but it’s important to consider what’s included (delivery, pickup, disposal fees) and whether there are any weight limits.Alternative Options:Bagster Bags: These are large, disposable bags that you fill with debris and arrange for pickup.Junk Removal Services: Some companies specialize in hauling away specific types of debris.

Think, I have FULL WEIGHT of liability on my shoulders for ANYTHING my agent's do.

would have to get a quote from an excavation company . depends on what the materials are for weight 

I have not personally held weight on the president dropping prices or increasing the prices.

People are crazed addicts for a single metric weight. 

Some GC's are only as good as their sub's and other's are better than their sub's and are worth their weight in gold - it all depends.I've don't most of my projects with sub's for many years and have learned to recognize many things that may need more attention, etc.

If your PM is worth their weight, they are using contractors with a proven track record that back up their work.