Yes.

D&D 4e is build on the basis that any specific rule that contradicts a general rule have priority over the general rule (Player's Handbook, pg 11). So, while Creature A can't reach Creature B, the power of the Skald Armor specifically says it can hit any creature that is adjacent to you, and thus, ignore the general rule about reach.

Yes.

D&D 4e is build on the basis that any specific rule that contradicts a general rule have priority over the general rule (Player's Handbook, pg 11). A character usually can't target something beyond their range. A power that allows them to target someone out of that range is an exception to that rule.

There are various examples of powers and abilities allowing characters to reach targets beyond their usual range like Orb of Deception or Elemental Escalation. Many soldier monsters also have an ability like that to take a hit in the place of another one, like the Phantom Brigade Squire's Shielding Martyr power.

Those "hit another target" powers have a clear intent. It is not supposed to fizzle an attack, but to make the enemy hit one of their friends (or a more meaty ally of yours). That, to me, means that the RAI has a very clear meaning that the attack will hit the target even if it is not within range of the original attack. There are precedents in the system for that and it makes sense thematically. They could easily change the item power to "chose another target within range of the attack" or simply "The attack will miss you" instead of the way it was worded if the intend was otherwise.