Ability Help & Uppgrades Help

Ability:
Hi, I am doing a map, I was thinking about a ability that damages an area, but I want that the are will be damaged several times, I mean like my hero should cast a spell multiple times. Lets say that I want that the firebolt should work like this:
1. I click the icon and selects my target
2.The hero casts the firebolt
3.Wait 1 sec and then again cast firebolt.
4.Wait 1 sec and then again cast firebolt.
5.Wait 1 sec and then again cast firebolt.
6.Wait 1 sec and then again cast firebolt.
I want it to work like this but that it don't costs mana and taht it doesn't have cooldown. (and I also need help on how to make a spell deal splash damage)

Uppgrades:
Hi, I wonder if it is possible to:
-Give a NeutralBuilding a Researches Available and that when a player unit is near the player can uppgrade, and this should affect only the owner of the unit, and also the other players will also be able to uppgrade.

Comment:
Please Answer Me!! :\

For splash damage, I recommend you use Frost Nova or Acid Bomb instead of Firebolt. Those are the only two single-unit-target AoE damage spells I know of.
You can make a dummy spell that chooses the target, and then create a modelless caster to actually fire the missile. This way, you can keep moving the unit to your hero's position and firing the projectile again every one second.

As far as upgrades, the best way I know is to make a hireable unit with all the tooltip and icon information of your upgrade, and then set the upgrade level of the upgrade for the (Owner of (Sold Unit)) whenever that unit is sold.