No. Grips and handlebars are fairly well standardized, so pretty much any grip will fit.
Depends on the diameters of the bars. Usually, but not always, they're the same and can use the same grips.
No, they come in all shapes and sizes
If the diameters by the clamp area and where the grips and levers goes are the same, then you just switch the bars.
Yes it is. It's not considered a top tier brand, but it's very good all the same.
The same way any bike is made. The frame + fork is made out of tubing, and then painted. Then the bike goes away to have all the various small parrts assembled.
Generic kids' shoes are usually made out of the same material as the brand names, but will have a shorter warranty and be cheaper.
A toilet tank made by a different brand may not fit properly, so it is better to get the same brand.
standard .45 grips, the same ones on the G3.
Yes, all handlebars have the same diameter out by the grips.
BMX bike ramps are usually made out of material such as chrome or aluminum. They have to be durable enough for multiple people to use them at the same time.