Welcome. I was hesitant to root my phone while I had it active because I didn't want to be inconvenienced with learning it and then dealing with all the issues. But the official ROM got pretty sluggish, to the point where it would take 4-10 seconds just to open up the phone.
I was only running Launcher Pro and a few other programs so it was not like I was running a bunch of apps on it.
I rooted and played with zRom using the instructions from here and sdx-developers.com , and the phone was much faster. But I noticed errors with certain apps like MomentFlash (flashlight app) and email settings, so I reverted back to stock, and then tried out Radioactive FroYo 1.8.22, which seems to be very stable and works great.
I haven't had a force close yet, and it is fairly fast. The stock ROM is just not optimized, whereas the custom ROM removes a lot of bloatware, and uses a more efficient kernal, so it really is a lot faster and better on the battery too.
And rooting is legal. With the Moment you can't really mess it up. It's super safe to try to root, and you get a lot more power out of it, including the wireless tethering app that you can use once rooted. Give it a try!
It's extremely simple to do, and once you've done it once, you'll be able to do it again in your sleep.