Here is a list of everything that I know concerning CaH that might help others:

Glitches:

Any Powers Glitch: When in Create-a-Hero menu, select a hero. Then select the powers tab, and select the hero again. Put your mouse cursor over the customize button, and click any arrow key and the left mouse button in rapid succession. The result is you will be able to give the hero currently selected the powers of the hero previously selected.

Elven Heal Glitch: The shortcut for this power is L. If pressed while the hero is moving, it recharges instantly, rendering the hero virtually unkillable.

Power Combos:

Anti-hero:

Cripple + Stealth + Arrow wind
Peppers the hero with arrows, while keeping you hidden and keeping him/her from escaping.

Blademaster + Heroic Charge + Mighty Spear Throw
One shot kill of anything in the game

Stealth + Wirlwind
Throws an invulnerable hero a great distance, giving you time to escape and wait out invulnerability.

Blink + Stealth
Attack when you want, who you want.

Summon familiar + Spear
Finds a stealthed hero and kills him. You wil propably need to use other abilitys with spear for a one-hit kill.

Summon reinforcements + Disguise + Heroic Charge + Spear
Summons Reinforcements, makes them and you alot stronger, makes you look like one of them, and kills the enemy hero while he is trying to single your hero out.

Curse Enemy + Stealth + Cripple
Resets your enemy's special power timers while he is looking for you, attack him, cripple prevents him from running away.

*This only works on some hero duel maps*
Blink + Blademaster + Heroic Charge + Sapper
Teleports outside of the arena area, and kills the enemy fortress in one hit.

Invulnerability + Elven Heal
Immunity from anything other than one-hit kills, avoidance of those with invulnerability.

Anti-Troop:

Earthshaker + Arrow Wind:
Throws enemies, shoots survivors

Call Reinforcements + Heroic Charge
Creates a nearly invulnerable mini-army. Good for flanking.

Wirlwind + Call Reinforcements
Forces the enemies to fight you, thus staying put and then getting thrown by your wirlwind.

Berserker Rage + Firebomb
Firebomb also recieves the damage bonus, so you can instantly kill weak enemies with it at level 2. Great for leveling.

Inspire Fear + Barrage
Makes enemies cower long enough to be smashed with your barrage rocks (unless they anticipate it and run before you come near)

Blink + Word of Power
Teleport to middle of enemies, and kill them all. Also works with Earthshaker and Leap.

Anti-Building:

Blademaster + Heroic Charge + Mighty Sapper
One-hit kill of unupgraded fortress

Other observations:
Any spells targeted at an enemy are affected by buffs such as Blademaster, Berserker and Battle Rage.
Putting Sapper on auto-set makes the hero use it on units.
Melee heros given toggle weapon still attack from close up.
You can still target invulnerable heros with special attacks, so check to see if they're invulnerable so you don't waste a good ability.

I hope all of these will help people. If you have anything to comment or add, post it here. Good luck and have fun!