tdcostas, I think you really messed my post at all... Also, you don't need a plugin for it, as the sample above, you can do it using events...
What you asked for is very simple, and possible to do inside C2 with by 5 events, pay attention to the sample and adapt it to your needs (using the tilemap instead of separated sprites).
Every tile in the tilemap can be checked and you can setup individual weights for it using a 2D array, with a line for X, Y and Weight.
Highlighting the area where is possible to move on will need the bubble logic of my sample, where you start from the player, going to the surround area, giving them a weight and limiting the bubble to a desired range. You will need it to avoid obstacles and turns around.
I could give you a sample, but been busy to spare this time now, hope luck to you... and peace...