- Yes, they did used to have a cost, but in this instance what we're talking about is the cumulative effect of doing this repeatedly, with the increasing cost of each settler, there is a break here.
- You need to specialise your cities to get the most out of them in this version. Simply spamming city on city is meaningless if they're not doing a lot, and investment in them early generally requires the work that's going into spamming more, either through settlers or through military.
- I may be mistaken as I've not dived too far into the maintenance mechanics, but there is a maintenance cost from cities from what I could tell. Equally, whilst you can get the occasional settler off your opponent, you'd be struggling to infinite city spam just on that.
- Being able to defend a large one is only easier if you have the military to do so.
- Except they do get annoyed at you for having a large number of cities, particularly building near them or quickly. Whilst I don't think the balance is tipped that way now, being dog piled while you've not specialised your cities could be devastating.