Just to clarify I'm not just another t@h user, I'm the de-facto lead client developer.
Just passing on tiles the client can't render would mean several tiles do not get rendered at all. So a more general solution needs to be found.
or/p looks promising on that aspect, it could make B) workable.

...and then there is openaerialmap, which might just work, if enough aerial photography enthusiasts work together...

if you want to watch your nodes you can tag them and watch them through the OSMXAPI osm.wiki/index.php/XAPI However I will wait for a proper implementation by bbox or polygon.

This comparison shows that some google tiles seem to lack that error
http://geo.topf.org/comparison/index.html?mt0=tah&mt1=googlehybrid&lon=-122.1243611&lat=52.120836&z=15

@tyll it is.
informationfreeway can also show the mapnik layer.

Deelkar, Bremen
53.0952°N 8.8652°E

A bike is the near perfect mode of transportation for mapping!

Looking forward to your additions.

Deelkar, Bremen
53.0952°N 8.8652°E

Grüße vom OSM-Pionier in Bremen
Ich freue mich immer wieder wenn ich sehe, wie die Stadt in OSM wächst :)
(Auch wenn ich selber in letzer Zeit eher wenig zum mappen komme, dafür wächst Osmarender/Tiles@home prächtig...)

To Alexander: That will only update the "osmarender" and "maplint" layers, not the "mapnik" layer which is the default map.

To hjw2: The problem with newbie documentation is that anyone learning the ropes has at first trouble understanding it, because there is no good documentation, then when they have learned their way around, they don't bother updating the information. Secondly traditionally the project evolves quite fast, so any documentation would outdate pretty quickly. (The process does seem to slow down lately, so the chances for good newbie docs are getting better)