1. There's a fair amount of customization, but not a lot. Depending on the profession, at character creation there are about 8 face options, 6 skin colors, 8 hair colors, and 8 hair styles to combine together. You can choose the character's height and the color of the starter armor. Once ingame, there are several armor artwork types to choose from and dyes to color them with, but no way to change hair style/color, face or skin color.
Check out this link for some pictures of different characters and armor types:
http://gw.gamewikis.org/wiki/Armor_types
2. The loading times can be long if one uses the default configuration, since Guild Wars defaults to only downloading new areas upon first visit. However what I've done after installing is to create an "Update" shortcut, which is a copy of the Guild Wars desktop shortcut with the "-image" switch added to the command line. Like so...
Copy the GW shortcut.
Right-click on the copy and select Properties.
In the Target line add "-image" after the command line, without the quotes. It should look like this...
"C:\Program Files\Guild Wars\Gw.exe" -image
Save the shortcut as "Guild Wars - Update"
What this does is opens Guild Wars and downloads ALL updates to your computer, then closes the program (can take anywhere from 15 minutes to a couple of hours, depending on your connection speed). You'll still need to use the normal GW shortcut to play the game. This makes the loading time negligible, since all newly visited areas load from your hard drive rather than downloading each new area. I'll run the update shortcut about once a week.