The "STP doesn't matter for 1H weapons" stance is a little bit old-hat. STP matters just as much for increasing WS frequency for 1H weapon users as 2H weapon users, but before Abyssea it wasn't worth trading off any Accuracy, Haste, etc for STP due to 1H users lower average WS and the need for every bit of Accuracy/Haste/etc that we could get our hands on.
"How much TP do you get per hit" is a bit of an open ended question, because it matters how much dual wield you use, what you sub, what your main hand is, etc.
15 STP on Fusetto +2 (with 15 STP from AF3+2, 5 from Rajas, and 1 from Brutal) with 48% Dual wield (Suppa, AF3+2 body, AF3 neck) and Kila+2/Fusetto+2 is:
(190+186)*.52/2 = 97 delay
(97-180)*1.5/180+5 = 4.3 TP/hit base
4.3*1.36 = 5.8 TP/hit = 15 hits to 100 TP assuming full TP return on Evisc
4.3*1.21 = 5.2 TP/hit = 17 hits to 100 TP assuming full TP return on Evisc
So 15 STP is almost a 13% increase in WS frequency in this case. This is kinda why the WS damage Fusettos are silly.
If you plug different numbers into the equations, you can recalculate for different combinations.