Most movement is "must do max". That's clear in most cases, especially when it's "retreat" or "close" or "advance". "Move" moves are less clear to me. Most notable is Mug Shot. It has "Before:Move 4". Do you have to move exactly 4? Most cards with move do specify if you have the option of moving less.... but I just wanted to double check.
How does the boost timing work? I see 2 possibilities.
1. They either immediately put the card you named with the boost into play as a strike, or they immediately reveal their hand (allowing you to memorize their cards) and then they put a card down to strike (which you have probable knowledge of).
2. You name a card with the focus boost. Both players strike. If the opponent struck with the card you named, game continues. If they struck with a card other than what you named, they reveal their hand to prove they didn't have it.
The situation's primary difference is whether you know their cards for this strike or for the future. I think it's more ideal if they reveal after, so that gameplay doesn't halt while one player memorizes a bunch of cards.... but I could be wrong.
New South Wales
Bennett from Brawl
Slow and Thoughtful
1. You can tell if you "must" do a move by the range listed. If it says "retreat 4", then you must retreat 4. If it is "advance 1 or 2 spaces", you can advance 1 or 2 spaces, but you cannot choose to advance 0 or 3 spaces. If it says "move up to 3 spaces", then you can move 0, 1, 2 or 3 spaces in any direction. The exception is the edge of the arena - if you retreat 4 and you are in the corner, then stay put. You can never move past the edge of the arena.
2. Do the things in the order they are said. So first name a normal attack. Then place a card face down for the strike. Then your opponent must either strike with the normal attack you named, or reveal their hand to you. So unfortunately you do not see their hand first. But if you like the idea of looking first then try Alice with Soul Eye - Divine.