4) is a little more complicated. FFG has said in an FAQ that if you want to interrupt a movement action of a big monster, you have to be able to execute the action from the 1 space your monster is shrinked down to.
No I think that's backwards. To be able to interrupt you have to be able to expand, you can't just do it from the single space you are shrunk down too. This came about in a ruling with the card "Nimble" on Wildlander. You can't use it to interrupt the monsters movement if it can't expand properly (it had to expand since it is being interrupted).
And since the monster can pick any space it occupies and shrink to that space, you are always able to get "that one space" that you want. But if you mean that you can't expand across a hero and then shrink next to it... yea you can't do that.
Also Thesues sorry I totally missed the familiars question. But yea each familiar will say "treat as a hero" or not so it's a case-by-case thing. For instance the Geomancer's stones are NOT treated as heroes, they are "objects". I think the necromancer and beast master treats it's Reanimate and Wolf as a "figure" but not a hero.
Edit: Here is what you are looking for from the rule book Theseus:
Some familiars, such as the Reanimate, are treated as figures (as indicated
by its Familiar card). These familiars block line of sight and movement,
but are considered friendly figures for hero movement. They may be
targeted and affected by monster attacks, hero abilities, and Overlord
cards that target a hero.
DOUBLE EDIT!: Nevermind DMaz I see what you are talking about. Yea you cant expand INTO a space that puts you in melee range, you have to interrupt movement with the square you intend to perform the action from, yea. You could still pull off my example though if you were strafing along side a hero.
Edited by Carbini, 28 August 2014 - 06:27 PM.