N5110 Stock stagefright patch info?

My wife's fully stock (4.4.2) N5110 started getting update notifications from Samsung Software Update.
Per the info, it's a 7.61 MB 'device stability and bug fixes' patch that includes security enhancements and StageFright fix.

1. Is there information on everything installed with this patch?


2. Will installing this block any future attempts at root / installing a custom ROM? (If she ever lets me; this is solely her device and doesn't care about root/ROMs ;) )


3. Since this is a wifi only note8 - how vulnerable is it to stagefright if I don't patch? Everything I've read says 'stagefright is more than an MMS vulnerability' but then the details only go into the MMS vuln :|

Thanks in advance and sorry if this has been covered elsewhere - I searched and didn't find anything.