Yes, they are rare, mostly always borosilicate is used for pipes. The heat can cause a pipe to break, while a soft glass water pipe still uses a boro bowl and slide.
Glory holes are used for soft glass, and torches are used for both. A really hot torch is used for borosilicate glass
No, mostly always a soldering iron is used, maybe there are times but mostly no
It is metal, very very thin. See more of what dichro glass is
Really it is about the proper temperature of the glass. But even if you get them, you can many times melt the glass so they are not there any more.
Sandblasting or grawling will always put stress in the glass. Some glassblowers after cold working it, they will still aneal the glass again
Opaque quartz is actually a whipped quartz and it is small tiny air bubbles. Or a cheap way is to just sand blast it. They are not the same though, they just appear the same.
These poker chip guards are used for people who play poker. It tells the dealer they are not folding.
This is also known as devitrification. This can happen yes because of a flame chemistry that does not work well with a particular color, or it can also happen when the glass is overworked and the sodium is burned out. A good blower also has tricks to help with this.
Yes, but Pyrex is just a brand. Boro is what pipes are typically made of in our industry. There are other brands such as Shott, which is what we mostly use, Simax and a few others.