Thanks! Is there any penalty for being in a deficit (other than the obvious)? Also, what do people normally set their research down to when rushing? Should you go straight to 0% or just have it at a low number (30-40%)? Finally, should your cities just spam units nonstop, or should they build the more essential building too (i.e. Courthouses, Barracks, Stable)? Thanks again for the help.
No, no penalty for being in the red other than the fact that you're losing money and may eventually run out. If you're playing with random events on, try to keep some money to buy off negative events or purchase better options of the good ones--around 100-150 gold in your virtual piggy bank should do it.
When I rush, I set the slider as high as I can without going into the red. When I gain pillage or war booty, I'll push the slider up to devote it to research until the treasury is back down to my aforementioned lowest limit.
In an ultra-early rush, you'll lose a lot of units since you don't have catapults to eliminate city defenses and cause collateral damage, so keep building more. At a certain point you can stop when you sense your victory is nearly complete.
The two most essential early buildings to support the early rush are a Granary to support regrowth after whipping and a Barracks for the XPs. As for courthouses, if your first war starts around the time they're available, you're not rushing anyone... you've waited too long. Ditto for stables, markets, etc.
Can anybody tell me if it makes sense to make a commerce-espionage city? I've got the GP farm, a handful of hammer cities, a couple commerce-science cities, and a couple commerce-money cities. Would it be a good idea to have one commerce city focus on Espionage (spy specialists, settled Great Spies, and Scotland Yard) if I'm only going to be running the slider at 10 or 20 percent espionage? Thanks.
It doesn't make sense to convert a
commerce city into an espionage city, but it can make a lot of sense to convert a
specialist city into an espionage city. In fact, that's often where most of my espionage comes from. I rarely run the espionage slider at anything other than 0%. If I pop a GSpy I'll usually use him to build Scotland Yard in a decent specialist city (not my GP farm, though, unless I'm playing an espionage strategy). Any GSpies after that get settled in the same city (or used for infiltration missions if I have an advanced rival with lots of juicy techs to steal). Run spy specialists there and prioritize the espionage buildings.
citizens each time. Not in every city, just your biggest, most important ones where you can least afford it. 
per city with that religion) which is independent of your research slider. This wealth is multiplied by buildings like the market, grocer and bank (and Wall Street, of course).
