Here are the answers to your questions:
Playtested this game at Essen and picked up my copy immediately! Love the tense PvP stealth mechanics.
A couple of rules caused confusion though - so here are my questions from our firat 'proper' playthrough:
1) When placing a yellow gem at the start of the turn, does the distance-from-thieves requirement include sewers? We had a case where one player was stood on a sewer entrance and wanted to place the gem on a sewer exit. I considered this to be one square away (i.e. sewer squares count as adjacent), but the other player disagreed. Who is correct?
The other player. Entrances to and exits from the sewers are not adjacent/connected spaces.
2) When moving through sewers your movement ends - so you are left stood on the sewer exit when the action card is fully resolved. Can you make further movement (caused by an Action card e.g. Potion of Speed) during the same turn? This was explained during our playthrough as "your turn ends" but the rulebook implies that you can continue to use actions after you come out of the sewers. We've been playing to allow extra actions after using the sewers, but it does make it quite easy to escape the Palace...
Thanks for a great game!
Sewers end your movement but not your activation. You can still move with other cards like Potion of Speed. Yes, if you are properly prepared and equipped with many movement cards while stealing the jewel, you can escape from the palace quite easily. Unless other player have cards like Automatic Snare of course.