I've used up most of a spool of HatchBox PETG in White. It was the first non-PLA I tried, so I had a bit of a learning curve. Once I got it all dialed in, it worked fine. One big step was using hairspray on the back side of the glass build plate. That gave me good adhesion, but the prints pop right ...

Moving the filament drive gear forward helped. You want the filament path to be centered on the gear. Unfortunately, by the time I discovered that issue, the plastic drive housing had already been worn so that it was still possible for the filament to go off track. Replacing the drive housing fixed ...

Not that I know of. I had several early prints that mysteriously died overnight before I figured out the USB hiccups when the PC goes to sleep. I have the LCD controller, and print using the SD card interface in that. Things may be a little different if you are using the built in SD card slot, but i...

I have used glue stick and hairspray on the glass side. Just flipped the plate over. HOWEVER, I also took a micrometer to the build plate and discovered that it wasn't uniform thickness. Mine was a tiny bit thicker at the back than the front, but the sides were pretty equal. The difference was small...

Brass is probably a slightly better thermal conductor, so it might maintain temperature out to the tip a bit better. As a practical matter, I doubt you could tell the difference, but more experienced users may have more info.

One trick referenced in my filament drive thread is making an improved drive bearing arrangement with a groove in it to make sure the filament can't wander. It was used to provide reliable feed for a flexible (rubbery) filament. It's not a quick fix, and requires some machining. http://forum.makerge...

I believe torching it off is traditional. I have a brass one soaking in "Zar Paint and Varnish Remover" which is 90% methylene chloride (very nasty stuff). It loosened a lot of it, but it didn't dissolve it as quickly as I had hoped. I have found that the stainless steel nozzles seem to clean up muc...

If it's the fine nozzle, try slowing down your print speed so it has time to melt.

Also, age in months isn't so much the issue as how many spools of filament you've put through the drive. Mine started getting flaky after about 5 spools worth.

You might check out this thread on my filament drive problems: http://forum.makergear.com/viewtopic.php?f=7&t=6565 In my case, the filament drive path had become worn due to a couple of issues. This allowed the filament to flex enough to slip off the front end of the drive gear. Relocating the drive...

Glad you got it sorted out in short order. For the Z-Axis knob, there are several designs on Thingiverse for "Z-knob stops". Some require printing a new knob, but here is the one I like: https://www.thingiverse.com/thing:1027536 You can also flip it over and use it as a crank to manually run the bed...