Verizon unlimited data tethering? Hotspot?

[AC Question]

I have a S3 all stock running 4.4.2 and this is my original phone from when I pre-ordered to keep my unlimited data. Unfortunately my income has changed and I'm looking to cut back on monthly expenses. First, is it currently legal (meaning Verizon can not alter my plan in any way without my consent) to tether or use my phone as a hot spot for my laptop without paying any kind of monthly fee? And second, if so, is there a way to do it, where I can continue to use my phone normally (calls, texts, email, etc) without having to invest anymore money into a phone I will be upgrading from shortly?