Hi Fred, sounds like a great story, love the killer nuns. I'm also working on my synopsis and hope to post it soon. It's really tricky, isn't it? So much has to be taken out.
These are my notes. I've not yet looked at the comments above because I think it helps to know what people think on a fresh read. I'll see what they say I've written this.
Chiefly, I believe, agents will be looking for an emotional ark to your characters journey, interwoven with the action. What was his inner normal in the beginning, how did he change at key points (perhaps at the midpoint) and how did the story fundamentally change him in the end.
Also how does Frank feel about all that is going on. Don't flood it with emotion, but indictors that make Frank human would be great. 'Frank was devastated when...' etc.
I've read that agents only want to see four or five main characters in your synopsis. If they can be left out (i.e. they are a subplot) then leave them out. It's also fine to refer to people generically (is that the right term?) without mentioning names, such as 'the killer nuns'. As I understand it, cut out everything that doesn't lead to or set up your big finale. Also, I don't think we need the Pope's name and the beekeeper at the end (as the beekeeper's role was not defined earlier). And the law firm's name doesn't need to be highlighted (only character names). I like the first mention of character names in capitals. but that may be a personal preference.
I personally wouldn't leave it on a cliffhanger -- the one nun left alive. I think agents want to see everything nicely rounded off. You can always talk to an agent about sequel potential if they are interested.
I really like 'His is a disjointed world where quietly-spoken nuns are assassins; cardinals are crooks; a CIA agent is a mass-murderer and a ferocious dictator is his only protector.' I believe it is in the wrong place. Might make a good starting hook, or be great in a query letter.
Be clear as to what is the status quo, the initiating incident, the development (possibly based around the turn at the midpoint, the big show down, and finally the resolution. so the agent is clear what happens at each of these points.
Perhaps it is a good idea to set the tone of the novel. For example, 'a network of psychiatric clinics', could become 'a network of sinister psychiatric clinics', if that suits the story.
'Frank will discover' -- keep it in the present tense, not future or past. 'Frank discovers...'
Good luck with it!