A character who may not take normal armour (ie, has no option for normal armour in his army list entry) may not wear magic armour. A Battle Standard Bearer who cannot have a normal shield cannot take a magical shield. Similarly, a Battle Standard Bearer is not allowed to take magical weapons that require two hands. However, note that these last two are specific restrictions for Battle Standard Bearers - a character who does not normally have the option for a great weapon could still take a magic weapon that requires two hands to use. for example. The same goes for ranged magic weapons - you don't necessarily need a mundane missile weapon option to take one. Only Wizards can take Arcane items. Some characters (such as Slann Mage-Priests, or Dwarf Daemon Slayers) may have additional restrictions or allowances.

No.

Yes. Page 152 states "A character who has a magic close combat weapon cannot use other close combat weapons". A character with a functioning magic weapon must use it.

Characters come equipped with a hand weapon, so they'll have to use that instead.

No, magic weapons and shields don't grant the bonus Armour save, in any combination.

In a challenge, only the model engaged in the challenge counts as being in contact with the bearer. The Direwolf FAQ Council has used the main challenge rules in conjunction with the detailed description of the Tomb Kings magic weapon, The Destroyer of Eternities, to arrive at this answer.

Yes. Any attack from a magic weapon counts as magical.

Any item which does direct damage and originates from a source not in base contact with the target. This includes hits from missile weapons, war machines, template attacks, etc. Note, however that the only spells which constitute "missiles" are those specifically noted as "magic missiles". Also, just for the record, a Banshee's scream is not considered a missile!

You roll to see which wound was inflicted first.

In cases like these, items should be treated just like a Ward save. So, if the save is passed, then the character takes no damage, and the wound rebounded. However, just a single wound is rebounded, not the killing blow itself.

A. No. It says in the description of the item that it needs to be used "as soon as a spell has been cast." If the spell was cast in the previous turn, this won't be the case.

No. It states that 'fleeing Wizards are not allowed to cast or dispel spells'. I'd say using a Dispel Scroll counts as dispelling a spell.

No, a power stone cannot be used on its own.

No. The general rule is that characters may only be equipped with one magic item from each category (Magic Weapons, Talismans, Arcane Items, etc.) While Wizards have been granted an explicit exception in the Power Stones description which makes it possible for several Wizards to carry Power Stones and for a single Wizard to carry more than one, they are not given an explicit exception to allow a single Wizard to carry Power Stones and another Arcane item.

No, unless specifically stated otherwise (for example, Skaven) a unit is only affected by a magic banner if it is in the front or fighting rank.

No (with the exception of magical banners that affect rally attempts or automatically rally units).

These items have no effect on the Casket of Souls or the Anvil of Doom, even if they can affect bound items.

Yes. The instructions in the Rulebook for a D3 begin: "Roll a D6 and halve the score." A player may re-roll the result of a D6 prior to halving the result to generate the D3 result.