I would put in corrections, but it would involve writing all new sentences, which you said you do not want.
If you want quick and simple answers,
1. No real difference. Both use same consumables, machine is rated for thinner pierces because it can't angle in, like a hand torch
2. Every plasma is different. you can vary amperage and speed to get best cut.
3. yes, mostly
4. Finecut is made by Hypertherm for use with Hypertherm only. Has specific uses for thin material
5. You are referrring to high frequency start or touch start. TD does not use these. = good
6. Always ground to plate
7. move torch tip to plate and set that as "Z" zero
8. You are referring to "leadin/leadout". Yes, this is done with plasma. Look at www.sheetcam.com for a better idea
9.yes, and the relay will stay on the entire cut time
12. for a digital Torch Height Control, yes. No THC means no voltage measuring
13. better left to Torchhead(www.Candcnc.com)to explain
14. M code will tell torch to go on/off
17. exactly. Devil x2
Sorry for not correcting yours, but this was the easiest and most direct. Need more in-depth? just ask.