I don't know anything about your phone or Sprint.
But, most Android phones can be "rooted" one way or another.
Certainly the web has enough info to find out.
A possible problem can be that the provider detects "tethering",
and does something about it. I don't know anything about the details.
My son has T-Mobile (Chicago area). He has a "pay as you go" plan that
give him unlimited text, a fixed number of minutes talk and unlimited
data for $30. You have to 'refill' the $30 each month. I thought the
talk minutes were about 200 or 300, however, on their website it appears
to be only 100. The unlimited data is throttled down in speed after you
reach the 2G (I think) amount for the month. With the relatively few
talk minutes, he as an app on his phone that allows him to make phone
calls via IP. I have talked to him on the phone (part of the 100
minutes talk, not IP) while someone else in the car was connected to the
phones wireless router and it worked ok. A few burps now and then, but
generally not bad. I wish I could get that plan here in western NC,
however, in my area, his phone roams to AT&T where, I don't think you
get these features, only talk and text, and usually a poor connection,
at that. I'd like it especially for traveling in the motor home. Most
RV parks have some sort of wifi, mostly free, usually just so so. But,
in some areas, there is nothing. It would be nice to be able to use the
tethering to do a few things on line. Oh well, maybe someday.