Tried it but it still looks very strange to me With the arrows I feel like someone is pointing out the obvious to me without any reason to do so.

I believe that there shouldn't be any artificial, direct visual attachments associated with the players in order to keep things in semi-realistic concept. The arrows could work, however, in a situation where the player needs to control artificial objects, maybe the arrows could be made active while pushing/pulling objects, or in a situation where the non-player model is being controlled (if we should have Golem or robot control in some level). But, as for me, in that situations I would still prefer the circle with the knob to appear around the model (Golem or robot) instead of arrows.

In any case, I do find that well positioned, nicely designed & animated circle-like object would be much better then objects directly attached with the player models.

...
But when talking about the mouse-only movement concept I believe we should also consider what would be a better selling point, since we are making a game that should have commercial potential once it's finished. It's true that from visual point of view having a cool-looking, animated round object with a discreet light-effects as a movement-control object is great & very interesting for viewers but is it better from the actual movement-control point of view? We mustn’t forget that pc game consumers are use to having a classic control systems depending from the game type. We should be very careful not to lose customers because of un-ortodox movement control system.

I'm not, nor have ever been a social researcher & I have no idea what market effect can this control-switch have on our project but I know that, in my experience, unusual things always go unusually up or unusually down We just need to, somehow, calculate what's most probable outcome.