Flying 101, slow flight, is that the slower you go, beyond a certain point, the more power you need to overcome the drag.
Definitely.
Configured that point is about Vref.
Hmm. That's an interesting proposition. Vref is an artificial construction ranging from about 1.2 to 1.3Vs in airliners - if it happened to be the best gliding speed in a particular airframe that would be by accident rather than design. In many jet aircraft, the last stage(s) of flap are there to add drag so the approach can be stabilised; this has the effect of increasing the curvature of the 'polar' and so bring Vs,Vx & Vy closer to each other. Having the gear down doesn't help, either.
I think most advice about gliding powered aircraft is written assuming a clean configuration... The wheels/flaps only come out when a landing is assured and you need to lose some energy. A 777 gear down, F30, Vref and no power I'd reckon you'd be lucky to get 7:1 out of it, rather than the 19:1 you need for a 3deg glide.