Our group are currently playing through the Heirs of Blood campaign. We've got some experience of playing MtG and other fairly complex card games, but this is our first time playing something with miniatures. We had a couple of questions that we didn't know how to resolve from our game last night, and I'd be interested to hear your input.

1) Our Necromancer has purchased the Mana Weave item. He activated his Reanimate, and when the Reanimate attacked he wished to use the Mana Weave to add a surge to his (the Reanimate's) attack. We were totally unclear on whether this is allowed - on the one hand the Reanimate does not have the Mana Weave equipped, but it feels like he's under the Necromancer's control, so maybe it should be OK?

2) This one is trickier. We found ourselves in a narrow corridor that a large-based monster (a Merriod) wanted to move down to get behind the heroes. I've included a picture of the setup. There was a 2x2 space which he could reach behind the heroes, using all 3 of his movement points. However the back hero was Jain, who can use Nimble to move when a monster moves near to her. She intended to move up if the monster moved towards her, which would then block the square.
Thinking about the order of events, the monster would move 2 spaces, and then when it entered the second square she intended to move. However, this would leave the monster unable to complete his move action, as there would now be no legal spots within 1 space of his position. His original intention was legal, her move was legal, but now we would find ourselves in an illegal position.
We decided that this meant that the entire move couldn't happen, so in the end I did something else with the Merriod. Is there a better way to resolve this? It seemed a bit weird that the hero could threaten to use an ability, never actually use it but still have the effect of trapping the monster.

1/ Mana weave is an item only the hero with it equipped can use it ... not his familiar nor anyone else.

2/ First point : Nimble is an 'interrupt' in order to use it you must be able to use it.
Second point : a big monster (anything more than 1x1) can only interrupt himself / be interrupted if he can 'expand' before

here the 1st point his ok .. but not the second
So in your example the Meriod shrinks moves one space, two spaces .. Jain wants to interrupt .. but as the Merriod can't expand she can't use Nimble !
monster keep moving and can expand in the place with the dots !

Side note before expanding Jain can try to use Nimble : this time she can but as when doing this the Merriod must first be 'expanded' Jain will be able only to move either to the left or back left (side by side with H)

By the way I advise you to take a look at the CRRG it contains 'A Lot' of Usefull Informations

Sorry to be slow to respond here - this needed moderator approval before it went up, and after a week of checking and seeing it hadn't yet been approved I gave up checking. Glad to see it finally went up, and thank you for the clear answers to both! Very helpful indeed.