whats the risk?

yes its worth it

despite what others will say there is little risk involved actually, just as long as you do ur homework and can follow basic instructions without getting ahead of urself

the key is to take ur time, yes its an exciting thought to root and mod and hack, but to do it properly u must first read, read, and read

It's actually pretty simple. First, though, I'd recommend  starting from scratch by flashing the stock dk28 official rom via odin, and a link to how to do that can be found in the sticky at the top of this sub forum.

After that, I'd recommend using the One Click Root method, which truly is the easiest and most stable way to root your phone, as it really does do it for you all with just setting up the drivers on your computer and clicking on the run.bat file.  It's what I've done, and it has worked amazingly well. IF you want the best of the best, use the one click method that flashes ClockWorkMod 3.0.0.5, which converts your file system to ext4, which is a more stable and secure, as well as faster file system the RFS that the epic comes with stock.
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Bonsai4All EXT4/CWM3 Compatible Rom

One Click Root package with CWM3.0.0.5 (may require logging in at xda forums, easy peasy)

XDA Samsung Epic 4g Developers Wiki -- All the info you would need with links to kernels, roms, official and unofficial sprint releases, as well as a lot of other useful general information.

Good Luck.

Good luck, and if you need pointers, let me know. Here's a couple places to start.