How do Mystics differ from the Alcolyte in the core book? Also can you talk more about the Prestige classes. I assume that they are 10 lvls and have requirments of able to cast some spell lvl, but what do they do? Just provide a path for further advancement?
"The New Age crystal healer. The voudun mambo, The revival preqacher with the magic touch. The motivational speaker that gets results."
Lacks the Acolyte's healing power, but has more flexibility in spellcasting. Same spell list, minus the healing spells, but knows more spells.
Class features include divine spells, turning undead, brew potion, discern lie, turn humans, empower spell.
10 levels. Preqs: Diplomacy (6), KNowledge (Theology and Philosophy) (6), Listen (6), plus a defined allegiance to a faith.
Do they happen to cover crafting magical items ala the DMG (feats, prices, spells needed, level req's, etc)? Or is just an expanded list of items.
No, just new items and references to the DMG for more.
How do they deal with law enforcement?
Do they just pretend it doesn't exist for the sake of adventure (ala. the wild west), or do the PC's have to constantly deal with the law via operating as part of it or as part of spec ops groups?
I don't think the setting is that specific. There's a lot of room in it to run the type of campaign you like, whether the police are present all the time or not. It provides details on police vehicles and equipment, should you want to use them.
Does this mean they haven't done anything to fix the bizarre 10th level mage "maximise" class ability?
Neither are reprinted in this book.
Does it have anything about the Shadow Slayers campaign model, or is it totally limited to Urban Arcana?
Well, the book is called Urban Arcana, and that's exacly what's inside. However, I think the two overlap so much and are so similar that this book would be equally appropriate to both of them. I remember reading the two settings in the core rulebook, and thinking "these are just the same setting with different GMs..."
Any chance we can see the stats on Synchronicity? (Has this book got any open content?)
No OGC. WotC usually release OGC via SRDs.
Synchronicity
Abjuration
Level: Arcane 5, Divine 5
Components: V, S, F/DF
Casting Time: Attack action
Range: Touch
Target: Creature touched
Duration: 10 minutes/level
Saving Throw: Will negates (harmless)
Spell Resistance: Yes (harmless)
Arcane Focus: A gold-level credit card or a garage door remote control.
Other than the examples metioned in the new item, it can also:
*Allow you to run at full speed through a dense crowd
*+4 Defense bonus when movement presents AoO (like Mobility feat)
*+8 bonus to Drive checks and can make unlimited avoid hazard and hard turn stunts
*+8 Bluff/Hide or Sense Motive/Spot when in vehicles
Which of the new Urban Arcana Advanced Classes best simulate the classic PC Core Classes from the PHB?
None of them, really. I guess the Archaic Weaponsmaster could be viewed as a Fighter type, the Glamourist as a Bard-type with no music, Mystic as a Cleric-type... depends on how tenuous you want to be with your links. They're different classes for a different game.
What's the difference between a Shadow Hunter and a Shadow Slayer?
The SH is more of a tracker or stalker.