I agree about the chests. I decided early on about which bonus set of equipment to wear and weild once I reached lvl 15, and sold the rest. I'm currently at 15 and still have 16,500 gold, and I choose the extra exp from quest.
Speaking of terrible loot... It's been 9 mths since I last played ED, and my memory is failing rapidly. Why are you stuck with Arben's Sword and unable to sell it? Is it bugged or is it quest related?
Arben's Sword is flagged as a quest item, and thus cannot be destroyed, sold, or even stored in your Battle Tower chest. The only way to get rid of "quest" equipment like it is to dispense with it via a quest or event. For Arben's Sword, the only way is to give it to the guy at the Slayer camp in Orobas Fjords in exchange for the key to get the Chalice of the Dragon (as part of the Orobas quest).
However, quest equipment (like quest items themselves) also don't count towards your item limit, so Arben's Sword isn't taking up a precious inventory space slot.