Speaking about safety:
It is obvious that choosing tube technology as first experience in electronics is not a right choice.
Risks are high because of high voltages used in tube technology.
I hope finom1 knows this and that he assumes the responsability of his choice.
He should learn about safety and pay attention to what he do.
For exemple, never touch a component and the chassis at the same time. One hand in the pocket is a very good safety rule.
Beginning with help of somebody who has experience in tube technology would be very helpful.
... things happen no matter how good or careful you think you are.
I don't agree, you must learn to prevent accidents to happen and that's possible.
Use your brain, work with safety and pay attention to what you are doing.
I worked all my life with high voltage, high power electricity and electronics, I would not be alive anymore if I had not learned to prevent accidents. (High voltage tests up to 150Kv, 120 Kva installed power test equipment, tests of 3000V 1500A rectifiers, test and repair of dc drives up to 8000A 550V dc, No-breaks up to 1 Mva, industrial battery chargers up to 600A 500Vdc, inverters, SMPS, ....)