I got a blob of around 5 x 8 cm out of PETG! Setting extruder temp to PETG or even a little higher. I did it all with an older soldering iron.
Simply (but carefully!) go with the point into the blob and take it slowly off. With a copper 'toothbrush', I cleaned the extruder and nozzle more times.
After mostly all was down I started with the first layer test (...
Even if it works properly (which it seems not to do), this type of thermistor will only have a resistance of around 100 Ohms at 350°C, which is too low to be useful in your printer. It is rather suspicious that the seller does not specify an accuracy for the thermistor, so it is probably of a low accuracy, which will make things even worse. I am not ...
The hotend itself consists of basically 3 parts:
The filament path, aka Coolend. It consists of the heartbreak, cooling solution and anything up from it.
The heater block, that holds everything together
The nozzle, in which the filament melts and is pushed out.
The part of the hotend assembly that gets to be in the most contact with the particles that are ...
Abrasive filaments require a stronger nozzle indeed. They also require an all-metal hotend. If your hotend wasn't all-metal, there's a good chance you've damaged it.
The PEEK/PTFE in your hotend doesn't like going above 240 Celsius and tends to be irreparably damaged if used too long above 250 Celsius.