Go to the Object Editor. Right-click the Dryad and select New Custom Unit (or something like that). Remove its abilities listed in the Unit Abilities field. Now go to the Ability section of the Object Editor. Find whatever spells you want to edit (Abolish Magic, for this example). Right-click...
You could make a custom unit for the Dryad, with modified spells that don't have any techtree requirements, and do the same for the others that are given to any race other than their own.
Seeing as you were unaware of this, I assume you don't know what it means. When you tell the game to spawn a unit at "random point in region", this causes a so-called leak. To fix it, first store the point in a variable, then refer to that variable when spawning the unit, like so:
Set...
Oh. Right. I don't have access to the WE right now, so someone else will have to point to the exact location of those actions in the trigger editor. :)
The game does tend to lose track of it after 10 seconds, yes. Although I've heard that Triggering Unit is kept in memory longer than the SPECIFIC ACTIONing Unit (target unit of ability being cast, attacking unit etc.)
I'm not 100% sure of what you're looking for, but can't you just grant Shared Vision of the unit to the owner of maphacker, and then remove it again when the requirement is no longer met?
Do you want the player to be granted control over the ranger, or to be allied with her? 'My team' implies the latter, but since the reinforcements are given to the player, I guess you want the same for the Archer. If so, above poster has the solution for you.
The *buff* doesn't affect the unit's stats, the abilitiy itself does. The buff just shows up as an icon at the bottom of the unit's "profile" in the UI, and may also affect the way it looks with attachments and/or effects etc.
Andrewgosu wrote a nice tutorial containing, among other things, a trick to do that. Here's the link:
http://www.thehelper.net/forums/showthread.php?t=34530&highlight=Spellbook
Not really, each aura just has fields for its own effects, like return damage or armor bonus.
Yup, it's quite easy really, set up the individual bounty rewards for each unit as shown above, and then use
Player - Turn Gives bounty On for Player X
and then killing that player's units will award the bounty.