On the male ninjas and the bigger you can do TP - JK - Spear - Invis - Autocombo for 56% demage and it will please most of your "it's not safe to turn invis off a throw" requirements. The combo does not require any extra set ups or an aaHP, they can be on the ground they don't need to be jumping, making this combo R.Smokes most powerful OTG...unless there's anything better (corners don't count).
So basically, his best OTG non-corner combos are (from hardest to easiest):
1) TP - JK - Spear - Invis - Autocombo....56% (Male ninjas and bigger, needs precise timing.)
2) TP - Run step HP cacel - JK - Throw - Invis....51% (Everyone)
3) TP - Run step LP cancel - JK - Throw - Invis....49% (Everyone)
4) TP - HP - Spear - Invis - Autocombo....47% (Everyone)
Any other combo shouldn't be done unless you want some variety.
Number 2 being the best (safe + demage), since there is no way to punish the invisibility after the throw, so scout whatever they are trying to do (Kabal spins, Slides, Teleports, Projectiles) and counter with a Spear ---> Invis ---> Autocombo
Most other useful information and combos for punishers I might post if people ask or if I find really good ones, but just look in the character guide for clear explanations for general usage of R.Smoke and punishers.