Actually, most stuff that is not TIGER (and even TIGER leaves much to be desired on many accounts!) will be missing regardless, and airports are just an example. The larger ones are likely to have been added by users, but the smaller ones, not so (I added three in Orange County, NY not so long ago).

osm.org/?lat=45.3614401272159&lon=-75.8256484001443&zoom=14

You basically turned what should have been "this area is water, it should be blue" into series of "this line is a river, it should be traced in blue, and everything on both sides of it is ground, and should be gray", so that we have "rivers" running along the shores and across the actual river...

Hey, you broke the map! You CANNOT make natural=water not be an closed area, that breaks every element of display.

If you want to show which area can be boated, your best guess is probably to draw a line in the middle of the water areas (which you will concurrent use for naming the river, because area=water riverway=river will not display names as far as I can remember), and use THAT to mark boatability of the river. As it is, the display practically unusable!

Maybe you can still fix this way in Grafham, which is probably some sort of path, but was accidentally labeled as amenity=place_of_worship when it was entered.

if you're iffy with it, you can alway twin tag, too.

Possibly the nature_reserve tag is simply not yet rendered?

Sports are leisure=pitch (regardless of sport), sport=x, which can be tennis, badminton, baseball basketball whatever. I have no idea where you got the idea that only European sports were catered to. It's not clear to anybody whether "football" is american or world, ("gridiron" could be used instead). Soccer/football for North America would necessarily be a bad thing. After all, routing restriction are explicitly country-specific anyway.

There are also surface=unpaved and highway=unsurfaced tags in use (both are rendered by mapnik, at least in some situations).

The second case is most times a form of highway=service

I doubt there's a mechanism to do the appropriate checks (the ideal solution would be to mix the mapnik and osmarender approaches anyway: use a different color for th area and icons for the node only). And such cosmetic changes are typically not worth making tickets for in my experience.

I've seen proposals for thrash can, and there IS a tag for trees, in fact :p

I'm myself not by on amenity=bench, but I can see where it's useful, and as long as it doesn't begin showing up and crowding out other stuff on the map, I'm fine with it.

After all, although not all data is used by the default map, the point is that it can be used to display whatever you want if you need it.

This definitely looks like it. It's clearly highway=trunk that won't be routed through.

You should also note that not every amenity or shop will show on the slippy map (either Mapnik or osmarender) amenity=kindergarten and amenity=town_hall, for example, do not IIRC. Most shops are also not displayed.

Wait, on closer examination: If the street market is a non-car street, I'd go for highway=living_street or highway=pedestrian with a POI noting the street market aspect. Streets that "belong" to industrial estates, but are not public access are simple highway=service with the appropriate access tags (likely access=private). THey are othrwise no different from a regular street running through an industrial area and should not receive any particular tag.

Regarding your first problem, mailing address is clearly in this case linked not to the street itself, but to a building/set of building/estate with a specific name. Your way of dealing with it appears appropriate to me.

For streets instead of area, it is abutters=. I could swear I saw somewhere a way to tag opposite way names, but I can't find it...

Amenities, like school, libraries, hospitals etc. Landuses can be interesting to map too. Admittedly, a lot of work seems to have already gone into fixing and improving the Tiger data (though the overwhelming poor use of _link tags in the conversion could still be corrected in a few places, e.g.)

Nope. I don't know what the name is (never really checked). And technically part of what is within that way is actual industrial stuff: I think a small hydraulics workshop is in there. I'm planning to walk the southwestern quadrant of the neighborhood tomorrow (I'm visiting for Christmas) to map the postboxes, so I'll have a closer look.

Oh... So THAT is the "Bezirksamt Mitte"! I thought that was a street name XD

Areal naming trends are frequents in non-spaking countries, though letters alone are a bit odd: it's ALSO geographically leaning for the most part!. A new developments not too far from where I used to live has street names in "B" (ALSO with significant geographic overtones!), another has stuff like "friendship street", "loyalty street", and another was all about wines. It's the norm, not the exception in Quebec.