I believe the 'problem' lies more in civics and game pacing. Additionally, its more accute in C2C than in Vanilla due to so much 'gold' manipulation being in place over 'commerce' manipulation. Original CivIV didn't make the distinction except through the slider itself. Maybe we should never have taken this step. I know that's an unpopular thing to say... And I could be wrong but if there is a glut of commerce, its more easily accomodated by ramping up tech costs further. Of course, that's going to exacerbate other problems.
But ultimately, we are not matching income with expenses. However, the more moderate approach, imo, is to do what I've been doing gradually but cannot be done completely overnight, which is to increase unit costs, both build costs and support costs. Support costs can scale as the game goes along and if build production costs are increased, not only are we able to increase the value of an individual unit, but far more gold is needed as upgrade costs get much higher, so updating your military becomes a very spendy procedure.
Yes, buildings need review and many are perhaps too strong at the moment. There are some glaring examples, such as the Magic Shop, where the amount is really much stronger than perhaps it should be for its era. Perhaps just some streamlining and balancing could help.
As for cottages... they're already struggling to be anywhere near as beneficial as farms and mines still. Downgrading them in any way will just make them completely useless. This is likely WHY they've been tweaked the way they have, to match with the value inflation on other improvements.
As for building removing... why don't we start increasing the build costs of some buildings so that it becomes a bit more selective what gets built? Just like the units, the production costs of buildings have some extreme scaling issues throughout the game and need to be more closely aligned to the chart I posted in the modder's thread. Would certainly give a bit more value and strategy to each build selection.
Mind you, I've always been that player that felt that I was never settled if I hadn't built everything I'd want to build in the city, but I've come around to feeling like it's nice to be challenged to keep up with buildings AND keeping a military.