You can 'search' based on tags .... : click on one tag in the list on the left, thn replace the tag in the url and see if it returns something

Coordinates are not very human friendly ...
When I use GMaps , I type the name of a city, place, street ...
But you can always alter the url with you coordinates (decimalize them first , then click on permalink and bookmark ...

For large rivers , there is a riverbank tag, used with a normal river tag associated with a name tag

I would say the same thing as rorym ....

As long as there are no victims to the flood ...

it works :)

osm.wiki/index.php/Platform_Status

Or here in german osm.wiki/index.php/De:OSM_Map_On_Garmin

Well, if it was in Potlatch , hope you were'nt in practice mode
To see the history , view the map , hit the + , check 'data' (you might need to zoom closer) then you can choose in the left column a way or node , then click on 'show history'...

That's why there is a menu where you can choose between start , play and help :)
You should have choosen play

Yes , a trace is not a way ...
You have to edit the map adding ways according to your trace ...

Yep , grave_yard is not rendered because the tag is for very small grave yards (what else ? :) ) around churches and so ....

osm.wiki/index.php/Bridge

I would put a traffif light on each node of the intersection ...
Another thing , the bridge should not start directly at the intersection so the 'legs' don't run over the other street...

Cross referencing from different map services(look that they don't use the same source provider , there's not a lot of them) , and paper maps (a lot of municipalities, cities gives those to their residents) should filter the Copyright Easter Eggs out ...

No , because of the copyright crap ... and because of the voluntary errors found in these...

(In any case , cross referencing is always best ...)

Just pass the tile ref to the script ....

Well a point does not have any dimension, it's logical that when you zoom to have more details the point doesn't grow.
This gives JOSM almost no limit in zooming-dezooming an area like any cad/vector software.
I use Potlatch mainly when I don't have access to JOSM wich is not often since it's on my USB key and I carry it with me.

You don't even need a car , I've mapped my town and surrroundings with only my own two feet(I've some kind of allergy to biking...) and a GPS unit ....
It 's good for OSM and for my health ...

One way of lightening the work would be to layering the data.
Leave only basic map data like roads and landuse on base layer, then make additionnal layer(s) for amenities, shops, ...

On server side , why not try to squat Google servers ?? it would also improve map data on Google Maps in some parts of the world ... :)