1. possibly used
2. plasma is WAY cheaper, laser uses "laser grade plate", for most stuff plasma is good enough.
3. If you are handy you can build the whole system, with an open control (mach3) for less (including labor) than most turnkeys.
4. Don't know, I quit looking and built my own plasma table.
5. Yes a portable can be hooked up, one can use a hand torch, but a dedicated machine torch is much better. Most "consumer" (sub 100amp) plasma cutters have a torch and/or lead set that can be changed in minutes.
6. NO! These are 2 totally different beasts
On all equipment there are 2 levers...
Lever "A", and Lever F'in "B"