Generally, solder chips are better (all the chips that are no-solders can also be soldered). If you use a nosolder, or choose to not solder a chip, then it might slip out of place. Most chips that aren't soldered have to be re-aligned every now and then.
To play on XBL, you do need an on/off switch or you will be banned...perminately
I suggest you get the X2-lite, it is preflashed, is a solder chip (but has an add-on that costs extra to make it a no-solder), and works with all versions of xbox. If you want to see what version your xbox is, go to
www.xbox-scene.com . There is a link near the top to a "version guide".