Tyres/tires are the rubber things that makes contact with the ground, they don't come with spokes.
Rims are the (usually) metal hoops that the tyres/tires sit on, and they too usually don't come with spokes.
Wheels consist of hub, spokes, and rim when you buy them. To make them rideable you need to add tyres/tires and tubes.
Kinda-sorta. If the new rim has the exact same diameter where the spoke nipples are, then you can reuse the old spokes and hub. Easiest way to do this is to tape the new rim alongside the old one. As long as you get the alignment right(valve hole, and left/right staggered spoke holes...) you just move one spoke at the time over and you're done. Keep in mind that it'll take e it apart, but be sure to check the hub to make sure that it won't be seized or the flange is broken and the spokes aren't broken too on the old wheel.
They are reputable. new Fords come with them & maybe others.
Goodyear LS
Just go to your nearest bike shop, if you can afford it (and you need it) buy a new back or front odessey rim and tyre package if not just buy the tyre.
DOT minimums are 2/32ds for trailer tires and drive tires, and 4/32nds for steer tires. New from the factory, it varies between tires. Drive tires may come new at up to 28/32nds, while steer tires tend to be closer to 19/32nds new.
You need a a spoke wrench to get the spoke out of the spoke nipple by the rim. The nipple screws on and off just like a regular nut. Undo the nipple and bend the spke a little until it pops free. Unlace the spoke from where it's intertwined with the other spokes until it can be released from the hub. Bring the spoke with you to thebike store and buy a replacement, then repeat in reverse. Tension spoke until it gives of the same tone as the other spokes then plucked.
No, it did not come with them 10 years ago when it was new.
BMX
new tires. If the tires brake, you'll need it
You can find the cheapest tires in your area by checking local retailers. In some areas the tire company will come to you to fit the tires and will supply good quality tires at a cheaper price than many garages.
No
Yes the new tires are faster and do not slip.