Having not played this yet, let's do some theorizing: Who wants this card? Our first guess might be low Will Survivors and Rogues, such as Finn, Skids, Preston, or Calvin. While this may help them pass a Will test (especially so on Easy where the chaos bag is more mild), +2 Will doesn't raise their Will high enough that this will really change a failure to a reliable success. In short, you can use a supply from the card and still be highly likely to fail.

I think the characters who most benefit from the Will boost are characters who have 3 (or more) Will already. This effectively adds a Guts to a Will skill check. A lot of Will tests are against a threshold of 3, which means that if you have a Will of 3 already, Tennessee Sour Mash puts you 2 over the threshold to begin with, which is usually a safe test on Standard. If your Will is higher than 3, then you are even more safe to test with this card.

Once your supplies are gone, you may want to use this for the Fight bonus and maybe take out a small fry enemy. This is honestly the least beneficial part of this card, but at least it allows you to gain some value after this thing is empty (cough, cough, Mystic spell assets, cough, cough).

A lot of characters can take this card, but I think a few people actually like it. Let's review some interesting candidates. But first I want to add that we can eliminate all the people who get their out of class slots wrecked by dual class card rules, i.e., Zoey, Rex, and Jim:

-Agnes can test at 7 Will with this card. You might think, "why do I care about Agnes passing Will tests on treacheries? She's 2 up on tests against a 3 naturally." Don't underestimate this! Agnes regularly stacks horror on herself to activate her passive, deal with her Weakness, or (and this is the big one) use Arcane Research. Being able to all but guaranteed pass a Rotting Remains or similar test on a treachery is important. Plus, since she can deal 1 damage with her horror ability, the Fight on the bottle can help her take down a 2 health enemy in 1 test.

-Leo can test 6 on Will tests with this and refill it with Venturer. This combo makes him very hardy against treacheries and can help protect his low sanity pool.

-Yorick can ALSO use Venturer on this card, but not just that - he can put it back into play after using defeating an enemy. Which means, he can recur this card using its own Fight action.

-Finally, Rita can, just like Agnes, use the 1 damage from the bottle Fight action to take out a 2 health enemy if she combines it with an evasion. Rita also has a 5 sanity pool, so passing treacheries is big for her.

Those are my initial picks for this card: Agnes, Leo, Yorick, Rita. It will be interesting to see who the community ends up deciding actually uses this card once it is finally released.

• Can other investigators use the keys ability to move it to their play area when it's attached and later attach it themselves?
• If not, what happens when this card is moved to another player's play area with Teamwork? Is the new controller the only one you can attach and detach it? Or is the owner the only one who could detach it, after the new controller attached it?

Worth noting that this card can situationally combo with Quick Thinking (especially in a multiplayer game when you have more chances to commit Quick Thinking outside of turn). If you can use Quick Thinking to get an extra action when it’s not your turn, e.g. during the Mythos phase or during another investigator’s turn, you can use Coup de Grâce without worrying about ending your turn prematurely.

Bug card!

If you have already drew all of your weakness, it's a 2-2 ally cost 3 and 0xp but provide 3 search 9 for 1 effect, bug card.

if you still have some weakness in your deck, so what? For my experience, about 80% game I can draw all my weakness.So eventually it's almost same weither you use Rook or not. Is draw weakness early or on a specific time a bad thing? It's right for some weakness like Amnesia. But for most weakness I don't think so, because it means your is controllable, it won't appear on a inappropriate time that bother your crucial plan.

Overall probably the worst thing about Ursula downs is her special card. The bonus this cards is nearly non existent because you move and the enemy is still on you at your new location. Maybe helps get enemies closer to allys so they can fight sooner. Jake is a good damage soak though at 3/2. Overall id say hs is easily replaced by dr. Milan. However if you have him out before you get one let him tank a few hits first.