I played this game a couple of times, but I didn't finish it either of them. But it's a great game (I haven't finished Morrowind either). I don't remember the Elden Grove, if ever I reached it.
Exploit: you can find the Oghma Infinitum as many times as you want (hence the name) to make your attributes super human. Actually any artifact can be re-found provided you don't have any equipped.
All the information you may want, and then some, can be found in the Elder Scrolls wiki:
http://www.uesp.net/wiki/Arena:Arena