Force feels underpowered for a variety of reasons, imo
Main class skill (Photon Flare) is really bad (horrible uptime for a really weak effect)
Techniques are barely stronger than normals and the bonus damage from playing to their mechanics isn't enough to compensate
PP conversion is rendered almost completely ineffective thanks to new force gameplay revolving around using mostly uncharged techniques
When attacking, you are slowed down significantly. This is a huge nerf from PSO2, where you could glide around at full running speed while in cast animations - but I haven't tried out other classes to see if this is intentional gameplay design or just Fo
Force is the only (or one of the only?) class lacking a counter, instead getting a guard that refunds a little pp - when other class counters do lots of damage
You more or less sum up the issues with FO perfectly! I hope Sega takes these suggestions and looks at the class further to make it more viable compared to the other classes, I found PP conversion to be more useful as a subclass skill than for the actual FO which is...kinder weird. Photon Flare and TEs Shifta/Deband just don't last long enough, I kinder understand about Photon Flare since it's a potency boost but like you said, its effect is pretty weak for its uptime but again, this could be due to cbt and limited options. If they simplified the skill tree that much without giving the players freedom to create builds, that might not be for the best.
I think the class needs the most amount of work over other classes.