1. attack does damage to friendly targets right ?
Yes. The attack affects all "figures" in spaces adjacent to Leoric. Heroes and monsters are both "figures."
2 what does the text part ''this attack ignores range '' mean then. Cause if attack affects only adjacent figures and you don't really need range on it in a first place. does this mean that if i roll X on blue die i still hit or is there some other meaning in this wording?
"Ignores range" in Descent means that you don't need to roll range equal to or greater than the distance from you to your target in order for the (ranged) attack to hit. You still miss on an X, but you can't miss due to insufficient range. Granted, in the case of Leoric's ability, it would be difficult NOT to roll enough range, but it may be possible with some weapons to roll zero range.
also bit off topic does Tomble Burrowell's heroic ability count only grey die or all dice that come from armors of adjacent hero ?
It counts all defense dice from the adjacent hero. The adjacent hero's "defense pool" is all of the defense dice he has to roll. I would say tha toptional defense dice granted by a skill the adjacent hero possess probably cannot be added just so that Tomble can use it too (especially if the adjacent hero is not also being attacked), but any dice that this hero gets for free are definitely given to Tomble.