Umm... still didn't get it Raven. Sorry, I'm very noob at making shapes and stuff with small models and lights. I have no idea how to make it, please try and explain more accurate.
Tao... Let's take them one by one.
Magic Barrier (Whatever...): You obviously base it on Frost Armor and give a special buff. Now, make a trigger witht his form:
Event - An unit is attacked
Conditions - Attacked unit has Yourbuff
Actions - Create a dummy unit [note: dummy unit should obviously have no collision, be invisible, have locust and have the skill for stun... Hurl Boulder with no damage should do it]
- Order (last created unit) to Neutral - Hurl Boulder (Attacking Unit)
I wonder if this causes any lags or blockades though I doubt. If you make the dummy properly so it's not trackable on map, doesn't cost food and isn't a worker plus the stuff above there should be absolutely NO problem. I tried it

. You can also check if the position of the attacked unit is within 100 of position of (Casting Unit) for main melee because melee units tend to have this range. Is there another way Raven for the ranged stuff?
For the second one I don't really get it. Some said that you could make that skill an item skill or base it on an item skill. It should make it invisible but I don't know if it really works on not. And you can also increase the movement and attack speed yourself through triggers for the attacking unit and then just set it back (obviously will not be usable for more than one unit per player if you don't use JASS) to the original speed. Moreover, you can add the unit to an unit group and make another trigger which is activated every 1 seconds of the game as long as the group is not empty. It picks every unit in the ground and reduces it's current life by 4 or whatever. In this case you need NO SKILL to give and it's the most practical way. It may cause some bugs though, never tried it again.