ummm
answers
1, lvl 16 farming bow... coz thats generally what people use for real sp farming but I guess a lvl 16 spear r glaive would work dependin if ur mianly st or int.
2. ur choice, it just makes u strongerish but i've never noticed coz i use pots
3 16 same as you, like bandits and bandit bow man, lvl 16 stuff
4 um if ur mainly str then fire but you can also do electricity which people use for glavie (notice the name of the weapons eg lightning glavie gives u a idea what mastery is better for it sometimes) I'd say either fire or electicty, ur choice
5 um don't get the fire wall thingo, the concentration in lightning, pretty much anything that doesn't mention the damage it does or the protection it does aka mag attack 1374, mag increase 362 etc
6whichever u want, mana/int is good for people who use nukes, aka throw fire balls and stuff instead of physical(heuskal) attacls mostly, and health/str is good for people who just like to hack away at monsters
oh and it doesn't really affect the farming when ever u do it
hope this helps
Laios