What you think about mass removing area=yes from building= objects?
except building=no
yes, not massive improvement but it seems to be marginal improvement for me.
It will result in less confusing tagging and bring more clarity to newbies (both while editing tags and using data).
though I admit that one of main reasons for this is shutting up Osmose (I reinstalled Vespucci and have seen Osmose complaints, including this one)
bot edit approved here would be limited to USA
Seems fine by me unless someone can demonstrate a corner case where this is a problem. 
I see you’ve started doing this (which is very appreciated!). Do you have any sense of how long/how many edits it will take to go thru all the current cases in the US?
Currently completed, it was just few thousands objects. Could be done faster but I like to spot check bot edit as it runs.
As new matching objects appear bot edit may be rerun, this is triggered manually so if I am busy gap may be few months.