Jake Williams saved me from bad starts already two out of the four scenarios that I played with Ursula Downs. I bought Miskatonic Archaeology Funding first, so I can run Dr. Milan Christopher and Whitton Greene at the same time. Last scenario I had all three of them out at the same time. One move action yielding two cards, a clue and a resource? yes please!

The first ability just adds security in multiplayer games. Often I would say "Don't worry about enemies spawning at me, I'll bring them to you!" This saved quite some actions where one of the fighters might have come over to safeguard. The ability is good with Archaic Glyphs to also investigate and evade after a move. Great flexibility there.

Since the errata, it's hard to work out who the real Queen to use this pendant is.

Currently I think it might be Amanda Sharpe.

Using Enraptured behind Amanda Sharpe, you can try to keep your pendant topped up with charges and preventing it from removing itself from the game. Also, with Amanda's additional card draw (or rather card filtering) from her ability, she can see those Segments of Onyx faster than other investigators, without even trying.

TLDR: David Renfield and Well Connected are good level 0 card options

The Dunwich investigators just get more and more complicated to build decks for. As more cards come out, the possibilities for their 5 level 0 cards just keeps increasing. Two fun ones to consider are David Renfield and Well Connected.

Ashcan's ability lets you ready an asset once per turn. Now of course most of us see Duke as the 'real target' for that ability, but it does work for any asset. David Renfield is a very powerful way of piling up money, and even better when you can use him twice a turn to really fine-tune the amount of time before the doom threshold goes over.

Once you've amassed loads of money, you can now use well connected to easily be at +4 to any test, twice a round. Considering Duke gives an effective +2 skill, once you hit 15 resources, then well connected becomes a better option in a lot of cases. This doesn't mean Duke does nothing though, they're still useful for a 2 damage attack or a 'Move-stigate', and they still also give you that +2 skill.

There are many level 0 card options, here's a couple I tried together, enjoyed, and wanted to share :)

This card is a really fun Level 0 include for Ashcan. His ability lets him ready an asset, so you can use this card at level 0 twice per turn.

(Since they added the XP version of Well Connected this is less cool, but still makes for a fun deck)

TLDR: you have to choose something that changes the game state, if able

You cannot choose 'each investigator loses 2 resources' if no investigator has any resources. However, you can choose 'each investigator loses 2 resources' if one player has a single resource only. The game state changes by choosing that option, so it is valid.

From the rules reference:

Must

If an investigator is instructed that he or she "must" choose among multiple options, the investigator is compelled to choose an option that has the potential to change the game state.

In the absence of the word "must" while choosing among multiple options, any option may be chosen upon the resolution of the effect – even an option that does not change the game state.