You could just follow the code of conduct for large scale automated edits: osm.wiki/Automated_Edits/Code_of_Conduct
Specifically, discussing it before making changes.

And if you want to deprecate an existing tag and replace it with something else, you could follow the usual tag proposal process.

This is a fairly common problem in Mapnik, so I think its been reported a few times before. Mapnik always renders the symbol or name in the middle point of the area. But for complicated shapes, this sometimes means the symbol is outside the area.

See for example these reports on trac (not for parking, but its the same cause):
http://trac.openstreetmap.org/ticket/2306
http://trac.openstreetmap.org/ticket/2295

I don't know if these will actually be fixed any time soon.

The JOSM validator will highlight things tagged fixme.
Or this tool can show them as a overlay: http://beta.letuffe.org/

Though you should be able to download tracks and waypoints from the eTrex H, try using GPSBabel (assuming you have a suitable cable).

Worth checking your local area on keep right: http://keepright.ipax.at/
It warns of "intersections without junctions", ie places where ways cross without sharing nodes. So these should either have a junction, or a bridge/tunnel mapped.

I'd agree that is not helpful to do "connectivity fixes" in areas you are not familiar with, best to check on the ground if there's a bridge or not.

Or the fault of people assuming their map is correct, and not looking where they are going.
Was there not any warning signs, or barriers across the old road?

Check what projection you are using in JOSM - on Edit -> Preferences, then third icon down. It should be set to Mercator, then you'll get things the same shape as they are on the online maps.

I think a posting suite is several postboxes next to each other. Usually separate boxes for stamped mail and meter mail, maybe also separate for 1st class/2nd class mail.

I think a "drive through" tag would be useful, ie for things you can use without getting out of your car.
I'm surprised their isn't a tag already - not specifically for postboxes, but it would be useful for fast-food places, banks etc. I see there's a tag for service=drive-through, but that's for tagging the road that goes past the business, not the business itself.

I'd never heard of drive-through postboxes in the UK, though I noticed Wikipedia has an example of an American one (with a 'snorkel'): http://en.wikipedia.org/wiki/File:Drivethroughlaneatpostoffice.jpg

For adding pictures, you have to upload them somewhere else - eg to Flickr, Photobucket etc, or to the OSM Wiki or Wikimedia Commons (if under a free licence).
Then just post a link in your diary. Or I think you can use HTML tags, to include the image in your diary.

You could tag it as indoor=yes, to make it clear it is within the building (and not above or below the building etc).
Also, you could tag the building with its opening hours, which will imply you can only use the path during those times.

Have you seen this post on the Talk-GB list: http://lists.openstreetmap.org/pipermail/talk-gb/2010-August/010105.html
It refers to the map here, which is using OSM as a background: http://www.mczmapping.org/

Its an official thing from Defra etc, and it seems they are wanting to get the correct marine boundaries in OSM. So maybe they can supply the official boundaries under a suitable licence.

For the bicycle ramp on the steps, you can tag the way as ramp:bicycle=yes (plus highway=steps etc).
See osm.wiki/Key:ramp

So why did you add it to the map in the first place? What was your source for adding it? Is there a postbox at that location?

I don't think the Cloudmade Garmin maps are routable, are they?

I recommend this website, the maps are routable, and you can pick the area you want: http://garmin.na1400.info/routable.php

Or other options to download from this page, it lists which are routable: osm.wiki/OSM_Map_On_Garmin/Download

Where did you download the map from? What website?
Some OSM based Garmin maps don't support auto-routing, so the Garmin will just use the basemap instead.

See the page on good practice: osm.wiki/Good_practice
Specifically, this section (though worth reading the rest of the page anyway):

One feature, one OSM-object
Don't place nodes in (equally labelled) areas just to see some icon appear on the map. The renderers will display icons on areas as well and there's no need to have every parking-lot, soccer-ground etc. twice in the database.

Yes, its true that some renderers don't show icons on areas for some things, but this is a problem with the renderer which should be fixed. Don't have a node and an area, because that can cause duplicates in other renderers or searches etc.
If you're creating Garmin maps with Mkgmap, you can use the option "--add-pois-to-area", to get the correct POI icons and searches etc.

Or an easier option:
Load your waypoints in MapSource, then do "Save as", and save as GPX format.
You can then open the GPX file in JOSM, and it will show markers where your waypoints are. So you can add nodes on top of the markers, and upload to OSM.

I'm assuming the restaurant is open to the public, not just hotel guests?
One option is to have separate nodes, one tagged as tourism=hotel, the other as amenity=restaurant.
I'd say this is worth doing if the entrance to the restaurant is separate from the main hotel entrance. Also, sometimes the restaurant has its own name, different from the hotel name.

For the village hall, I think the best tag is amenity=community_centre
osm.wiki/Tag:amenity%3Dcommunity_centre
Though I don't think this is currently rendered.

Hello and welcome.
Have you seen OpenOrienteeringMap. Its an orienteering map based on OSM data. http://oobrien.com/oom/

See the contacts page: osm.wiki/Contact
Probably the best place for asking questions is the mailing lists. Specifically "talk" for general discussion, "tagging" for tag specific questions (like this sort of thing), or "talk-gb" for UK specific things, or "newbies" for simple / beginners questions.

You can also ask questions on the forum, but its not very busy, so you may not get as many answers.
Or the IRC channel if you want a more immediate answer / discussion.

As for your question, there is no need for relation for this. The best option is to draw the Tesco building as an area, tagged shop=supermarket, building=yes, name=Tesco (plus opening_hours= etc).
I think the building=yes tag makes it fairly clear everything in that area is within the "lockable confines" of it.