No, the minimized window does not show the health and mana stats.

But I agree, it would be helpful to let the current mana/health status show in number the whole time, on demand by the press of a button for example. Related to that, it would also be helpful to show the mana requirements for each ability on demand the whole time.

we just need UI mods to be allowed.

I agree.  You can hover your cursor over your health or mana bars at the bottom to show your current numbers.  However, by the tiem you've done this you've usually just gotten hit by that nuke.

I can see why the devs did this.  In my opinion, it gives a sense of excitement to this game that others don't have.  In DotA, for example, I can look and say "Well I'll definately kill him unless he's got [item/sill], otherwise I'm boned."  This is like Ooh what's going to happen?

Also, UI mods would just mean hax.

There was a UI mod in beta that did exactly what you want.   As soon as we get past the connection problems and can use mods again.  I assume this will be one of the first things that get released.