Search first post second..
All your questions have been answered many times.
Internet Sharing is not covered under the S.E plan just like either are the Sprint Tv premium channels. Tethering is not free in anyway its P.A.M (Phone as Modem $39.99 a month) on your bill if you pay for it.
If you do the reg edit it will work and you should slide under the radar and not get charged I have never had a issue with sprint over this.
Ya might want to be careful until you get your first bill just to be on the safe side, but again I have used it for over a year with no issues.
I have the S.E plan with no P.A.M. Another thread about it with some InternetSharing reg edits in post#2
HERE.
*Copy/Paste from OG post....