Let's say a half-orc rogue with the toothy racial substitution (gives them a 1d4 bite attack) makes a full-attack action.
Now his bite counts as secondary natural attack and gets a -5.
If he hits, would he get sneak attack damage on that, and all his weapon attacks? assuming target is flanked or flat-footed of course
Yes.
Yup
Yes
beware toothy half orc vivisectionist alchemists with claws and tentacles.
Pouncing druid rogues.
Awakened flying octopi with class levels in rogue.