Fighter + Ranger, Multiclassing and Marking

[vhailor]

1. If a fighter marks an enemy, that enemy takes the penalty to
opportunity attacks he makes?
2. A fighter and a ranger are adjacent to an enemy, and the fighter has
marked the enemy. The ranger moves away from the enemy and the enemy makes an opportunity attack. The ranger uses Disruptive Strike and the fighter makes an opportunity attack (Combat Challenge immediate interrupt)
Who attacks first?
3. Let's say a character (fighter) choose to take as second class rogue.
Does the character gain the class features from the second class?
Does he gain the first strike feature?
4. If a fighter multiclasses into wizard, and use Scorching Burst or
Thunderwave, can he mark all the targets in the area?

 

[Baumi]

1. If a fighter marks an enemy, that enemy takes the penalty to
opportunity attacks he makes?

If the opportunity attack is against someone else than the fighter then yes.

2. A fighter and a ranger are adjacent to an enemy, and the fighter has
marked the enemy. The ranger moves away from the enemy and the enemy makes an opportunity attack. The ranger uses Disruptive Strike and the fighter makes an opportunity attack (Combat Challenge immediate interrupt)
Who attacks first?

I don't know how it is handled by RAW, but I would let the players decide.

3. Let's say a character (fighter) choose to take as second class rogue.
Does the character gain the class features from the second class?
Does he gain the first strike feature?

No he only get's the Sneak Attack once per Encounter and a Skill like the Multiclass Feat for the Rogue says and nothing else. But afterwards he can take the other Multiclass-Powerfeats, Rogue Paragon Classes and Rogue Feats.

4. If a fighter multiclasses into wizard, and use Scorching Burst or
Thunderwave, can he mark all the targets in the area?

Yes, he can mark EVERYONE he attacks, even with spells or Racial Attacks (like Dragonbreath).