Birch laminate would be good, I think.

If you mean like the Earth and Moon pair, that could work. If you mean two planets in the same orbit, that would be unstable.

10x and over is very hard to hold by hand. Get a tripod, or at least a monopod, to go with it. Stabilized binoculars are very nice, but hugely expensive. There are cheap Chinese scope + tripod combos with provision for phone mount close to your price range.

Right. But that is not limestone reacting with water, it is CaO (aka quicklime) reacting with water.

The reaction from limestone with water is endothermic, it consumes energy. Limestone is made by tiny fossil shells piling up on the ocean bottom.

It would be a good idea to read "Newton's Clock: Chaos in the Solar System" by Ivars Peterson.

There are two ways to go, really. If you are interested in nebula, and faint objects like that, you need a lot of light gathering power but not as much magnification. If you are interested in the planets and higher resolution, the focal length of the primary is the most important. For nebula, a Dobsonian is a good way to go, also called "light buckets". For planets, a Maksutov (or "Mak") is a good way to go. For planets, you need a good quality tripod as well, motor driven is nice but not essential. If you can give your preferences and a budget, I would try to recommend some choices for you. You could step up a little to a larger refractor, like a 75mm achromat, that would be better for both uses.

This telescope has a 50mm aperture, so it will not collect a lot of light. The moon will be great, and you will easily see the Galilean moons of Jupiter, and the rings of Saturn. You won't be able to see any surface detail on Mars. You will be able to see some things like the Pleiades and some binary stars. You can see comets too when they are around. It is a nice starter 'scope, find out if you are interested in astronomy and if you want to invest in a more capable telescope.

It's a void that looks like a bird. The "underside" of the bird is just the edge of a cliff.

Try the Gutenberg project as a volunteer.

Might be able to mudjack it into being level. Contact a mudjack outfit for a quote. If they can do it, it will be cheaper.

In order to write the code, you have to pick an algorithm. This is the most important part of the job, always has been. AI may well write the code, but it will take a while for it to be able to select an algorithm.

I was thinking you might have to seal between the boards. The easiest way would be to tape up the bottom, and flow in coats of polyurethane varnish, and allow to dry between coats. Then power-sand everything. At least you would be able to wet-mop the floor.

Do you have access to the underside?

Time for Hanlon's razor: "Never attribute to malice that which is adequately explained by stupidity."

In agriculture, which used to be over 90% of the population, human labor is almost entirely replaced by machines.

Go by weight.

If the ocean were whiskey... Yes, I am that old.