You do not need an Xodus chip, no, you can use software exploits to accomplish this (007/raincoat, MechAssult/Evox, etc.)
Yes it is safe.
Yes, you can REALLY screw up your Xbox if you do not know what you are doing. The largest danger is from the fact that you have to solder at least two points on the motherboard, if you don't know what you're doing, or you're not careful, you can screw up your box REAL easy during this part, and then if you flash it wrong (which is a lot harder to do, but is possible) you'll need a mod chip to be able to use the box, and to fix the TSOP.