To me small 6 foot 1 inch diameter branches falling is pretty normal.

The problem is you could do 15 borings (which are less than 2" in diameter) and completely miss the problem.  

There were holes at least 2' deep (maybe 3') that had a diameter big enough for a spa. 

Seriously, when I have a drain that requires a professional to snake it, I pay $160 and that includes them either using a water jet machine or a industrial size snake with a 3/4 inch diameter cable.I'd say that they ripped you off.Mike

Has anyone dealt with a large tree stump, over 4 ft diameter, in the front yard?

Just in case you're in Seattle, I should mention that if the tree is larger than 6" in diameter, you'll have to hire an arborist first, and certify that the tree is dead.

I shine my flashlight up and see a branch about 4" in diameter sticking straight up on top of the trailer.  

Require the permitted junior accessory dwelling unit to include an efficiency kitchen, which shall include all of the following:(A) A sink with a maximum waste line diameter of 1.5 inches.

The hole inside the toilet bowl is about 2 inches in diameter and everything that goes through that 2 inch hole will absolutely go through a 3 or 4 inch sewer pipe when the pipes are in good  condition.

You may have to bring a wholes new waterline with a larger diameter line.