Staff Upgrade Questions...

Well this might apply to all weapons I'm really not sure. I have searched but have not found any posts that explain weapons upgrades well.

With Staff-Heads and Staff-Wrappings, I assume you are allowed one of each of these per weapon, so...

Question #1
How do I know which Stat my upgrade will replace on my staff?
i.e. If you have a Staff like the following... (doing this from memory while at work so forgive me if I make a mistake)

line 1) Fire Staff of Defense
line 2) Energy +10
line 3) Damage 11-22 (requires 10 fire points)
line 4) Fast Casting (10% Chance)
line 5) Armor +4
line 6) Health +27

Lets say you have a staff wrapping with Health +30, does a wrapping always upgrade a certain line while the Head allways upgrades a different line (like line 5 is wrapping and line 6 is always head)?

-Or-

Does a wrapping or head always upgrade the type of Stat (amor alwyas upgrades armor, health always upgrades health)?

The reason I ask is because I have wrappings and Heads that both have + Armor, and the same with health. Also there are upgrades for things like fastcasting. I dont want to apply a Armor +5 iif it overwrites my Health.


Question #2

Are there a set number of Attribute lines to a weapon, and what are they?

Naturally not all weapons have all the attribute attached to them , hence the upgrades, but I have seem some with additional attributes like Energy +1. Is Energy a new line a 7th attribue, or does energy overwrite one of the existing 6 lines?

I guess IM trying to figure out out of all the attributes how do I know what I can add and what I can replace to make my weapon the way I would want it.

Thanks for any help with this,
-Nim