What size branches do your trees drop Tiff? I would be scared to walk on your yard.
I've never bothered to pick up anything that's less than 4cm in diameter and I've never broken a lawn mower. Even the the regular 1hp two strokes.
Concerning Tiff's underground palace last page, you'd need a heavy duty air treatment/conditioning/heating units. Those aren't exactly cheap. They also need a shitload of energy to run. You'd either be burning a lot of fuel or have skyhigh electricity bill.
Depending on the place that's built you might be able to make use of geothermal energy for running your place but a place that size it would be somewhere between 50-100k extra cost.
There would also be the issue of moisture dripping through the walls that might make your pretty white walls turn grey rather soon. You'd have to have moisture seals aside from just using concrete walls. But basically you'd need to dig a hole almost twice the size of the end result because you would want to have it surrounded by better soil instead of whatever random stuff you're building on.
Not quite - http://www.tornadoproofhouses.com/indoor-air.php
Can't comment about the walls.
Those are the normal air circulation units that every house(at least here) has. The thing is that it isn't enough for an underground palace if you want fresh, not just breathable air. It just circulates new air from the surface to the house. Aside from a basic filter there's nothing to ensure that it's somewhat dry and somewhat warm. My experience is that devices like that are not enough if you want actually fresh feeling air, much less underground.
Another thing is that it needs to regulate the moisture in the air. Depending on your area, it might be very dry or, more likely, very moist underground.
The walls and the need for insulation depends on the ground you're building it on. Sand hill wouldn't need anything but a thin moisture seal while a valley with a lot of fertile soil would be a nightmare.
I'm no engineer in the area though.
Why the fuck can't they fix the wifi here at the uni? It's saturday and it's fucking overloaded again. WTF?