1. For each triggered splash damage card, who is choosing to destroy units ? Example: If I am attacker and I trigger two splash damage cards, its me who choose to destroy 2 enemy units at the end of combat, or my opponent is choosing which 2 own units to destroy (aplying rule to destroy as many units as possible)

2. Which type of attack (Ground / Air) has Hero unit ? It is correspoonding to the unit for which hero is assigned ? (I am confused because Kerrigan´s Psionic storm reinforcment card has also Air splash damage)

3. When executing Gold Research order could I take two event cards AND one technology card which is going to play area ? Regarding rules this should be possible.

4. in Brood War each race has one technology card, which allows to take one discarded technology reinforcment card back to hand once during turn. What is timing of this ability ? Can I return this card whenewer I wish ? (even for example in combat etc...) or can I use this only in some particular phase ?

1. The opponent.

2. The same like a standard unit of its type.

3. Yes, that is completely legal.

4. You can do that only when you're going to discard a card. That's explained in "new keywords" section of rulesbook.

Drakkkan said:

It's the same as the corresponding regular unit, although "Cloaking and Psionic Storm" does give Sarah Kerrigan ground/flying splash damage, despite the fact that her normal attack only hits ground units.