There must be something else at play in the Pax Cal. Im not having a problem with my flight. I use standard seating and offer all 3 classes. Starting turning a profit at around RI50. My route is not that much bigger at around 170 daily.
I think its the size/configuration of your 702 and your Arr/Dep time. 0500 Arr is why your return fight is low. I bet if you adjusted that you'd see an immediate increase on the return flight. Also, your oversold on the C class side... if you reconfigured for less, that would add Y seats and your LF for Y would improve.
Why? Well, IIRC the Pax Cal takes into account seats offered. It then assigns what LF it decides on (w/e the variables are). So its very possible to sell more seats via offering more seats.
Strange that your not getting that one F class pax... I guess they really want a premium F product for that length with a tech-stop.
Talentz