Yes
You can remove bearings from a BMX frame with a 'mid' bottom bracket without damaging them using a 3/8s rachet extension.
It depends on your hub. If it's unsealed, then the ball bearings have different diameters - you just need to find out which size you need. That's fairly easy. If it's sealed, there is going to be a number on the side of the seal - usually a 4 digit number starting with a 6. That number identifies your bearing dimensions, that's the bearing size you need.
No. Skateboards and inline skates all have cartridge bearings, while a lot of bikes have cup & cone bearings. For those bikes that do have cartridge bearings, their axles are thicker than skateboards/skates.
SKILLS!!
Wheel bearings, main bearings, connecting rod bearings, cam bearings, axle bearings, carrier bearings, pinion bearings and so on, need to be more specific.
Basically you need a BMX and somewhere to ride it. Helmet, maybe some pads and gloves would also be nice.
Sealed just means that water and muck can't get into it. Integrated means that the bearings sit pretty much directly in the frame. Regular headsets first have cups that sit in the frame, and then the bearings rests in the cup.
Wheel bearings? Axle bearings? Differential carrier bearings? Engine main bearings? Engine rod bearings? Engine cam bearings? Need more info to help you.
If one is looking to find a BMX park list in the United States you can go to a site such as USABMX where they have a vast majority of the USA's BMX parks. They also have BMX parks that are in Canada as well as the latest BMX news that you need to catch up on.
They come Krunk K2 bearings!
No, you just need to be able to ride a bike