1. Edit it manually. NPC shops on SCF files is configured differently from the original serverfiles. The 8th column is for the exc opt, you can make it FO (use 63 for full opt items) or you can make it just few opt if you want.
example (noob items with FO)
:
Code:
//HANZO the blacksmith [Lorencia]
// Index Item Level Dur Skill Luck Opt Exc Opt Item Name
1 3 9 255 1 1 7 63 //Tomahawk
0 0 9 255 1 1 7 63 //Short Sword
0 3 9 255 1 1 7 63 //Katana
0 1 9 255 1 1 7 63 //Kris
0 2 9 255 1 1 7 63 //Rapier
0 4 9 255 1 1 7 63 //Sword Of Assassin
0 6 9 255 1 1 7 63 //Gladius
0 5 9 255 1 1 7 63 //Blade
end
2. to make your character GM - you can use mumaker for that or config it on the SCF_GMSystem.ini located on GameServer folder in your server files.
for editing items you can use mumaker too, just search in the forum for that editor.
for the commands to many to mention but heres some example
GM drop command
Code:
/drop 0 22 13 1 1 1 7 63
it will drop a FO boneblade
GM post command it will show the GM message on screen
for other commands try searching on forum 
3. Rates of the server can be change on CommonServer and CommonServer_Cs (located at DATA folder in your serverfiles)
4. i dont have a monstersetbase for arena right now.. study the monstersetbase config so that you can learn to add mobs in arena
5 Server names can be change in text.bmd (client side)
theres a lot of good bmd editor out there just try searching
6. add items in the pointshop.txt located at the dat folder in server files
hope thats helps