Great guide, thanks for sharing. I just want to comment on this section.
I get the first part.... (I've been doing it like this, so I pay bills w/ 5 labor camps, then on the date I decided to back-collect (I usually go more than 5 days), I destroy labor camps and replace w/ other, collect, then the same day re-buy labor camps).
I just don't get the second part of this.... why every 2 days? Why not all at once? Is this the remnant of when game rules were different? If so, it should be updated (probably simply remove the entire second portion.
That last sentence is very misleading as well and should probably be omitted or rephrased. If you are already back-collecting, there's no reason not to combine that with improvement swapping. Sell x5, Buy x5, Collect, Sell x5, Buy x5 (every 10-20 days) is not that complicated. That second portion (and last sentence) actually deterred me from doing improvement swapping when I was already back-collecting because it made it appear more complicated.
Also, it should be noted that the savings increase significantly as you grow bigger.