Great episode. I find the start of this season an improvement over last season.

I assume the reason that Spartacus had to sneak in and raise the gate at night was that the gate would have been lowered if the Roman guards saw an army of slave warriors storming the city during the day.

 I like the historical context - looks like they're sticking to at least some of the history (the pirates and their betrayal).

I find it disappointing they are rehashing the "spurned wife" thread with Crassus.  How many times have they used it in the series so far?  We know it's going to  come back and bite him..

 The interesting thing about historical fiction is you know how it ends (Inglorious Basterds excluded). Spartacus, Crassus and Caesar are all big names in the history of Rome.

but I am really enjoying the way this is playing out.

 Man this season is really great so far and reminds me of why i loved the show so much. The appearance of Caesar has really put a great spin on the show for me, and played by an intriguing actor as well. 

Caesar had such a limited (if any) in the dealings with Spartacus.  I would eventually like this to lead to a spin-off series revolving around the First Triumvirate, eventually leading with Julius Caesar forming the Roman Empire.

STARZ is too cheap to take a chance on a spin-off , besides SPARACUS , every other series flopped . Thats why is is the final season for this show.