The question is, can you make something like this with the Unity 4.6 UI Canvas -- and the answer is yes.
Make a canvas, make a panel, make buttons.
Store your "skill points" either in a local variable on the player, in a global variable, or as an attribute; your choice.
On Click (this function is present on all Unity Buttons) trigger a plyBlox event.
In this event, you would spend a point, add the skill, and set that "interactable" checkbox (pictured above) to true, on the skill beneath it.
If you are not at all understanding what I'm saying, i'll put it in one of the videos, when they come out.
If you're talking about a tracker to show your progress in the "active" quests, I've never tried, but you can probably get it to work by making a text on screen, and setting it to reference the "quest conditions" perhaps?
you're on your own with that one, no idea.
quests are built into plyGame, all you need to do is make a Graph.
Leslie's Quest tutorial is in the plyGame documentation.
My tutorial (almost exactly the same) is here.