Hi Michael,
First of all, welcome to OSM and thank you for trying to fix the map data (even though it didn’t work out, but that’s nothing to worry about, seeing it was your first changeset and the editor didn’t seem to cooporate!)
After looking into your notes a little bit, it seems like Lunds kommun is reporting erroneous data to Trafikverket, since there are large discrepancies between street signs on the ground (as reported by you) and the data on NVDB (choose speed limit as a layer and compare to your surveys). Best would be if you could report this to the municipality. Even worse is that lots of the streets, and especially the living streets (gångfartsområden), don’t have any legal speed limits as the signs would suggest, since they would be listed under Svensk trafikföreskriftssamling - Transportstyrelsen if you choose region, municipality, mark all the boxes and search for a street name. This is as far as I can tell also a result of incomplete reporting from the municipality, which it ought to rectified.
For the time being, at least in Brunnshög, I would suggest trying to follow the speed limits as signed, seeing as the official data have random streets down as 50 km/h streets, which they obviously aren’t supposed to be. If there is a sign for gångfartsområde, the OSM tag should be maxspeed=walk, or you could tag it as 40 km/h as well, since the sign isn’t legally enforceable.
Trying to fix the behaviour of the application in your car by changing OSM data is wrong, though, if the data you’re contributing isn’t correct. If the speed limit is walking speed, it should be mapped as such, even if your GPS is wrong and penalises you in some way. As for the speed limit in the parking garage, I think it can safely be mapped as the same as the street outside. There would be no speed limit change by entering the parking garage if there are no signs, so even if you can’t drive even close the speed limit and there would never be any speed cameras inside the parking garage, maxspeed=40 wouldn’t be incorrect, in my opinion.
It looks like you added the levels correctly to the roads you added (they are now deleted, so you’ll unfortunately have to readd them), but they shouldn’t have any names that aren’t signposted. They should also be placed correctly geographically, so if they aren’t in a spiral, but in reality on top of each other, they need to be on top of each other in OSM as well. This is unfortunately very difficult to achieve with editors that lack layer support, which include many simple editors (I’m unsure about Go Map!! specifically).
I hope this explained some things and again, welcome to OSM! There are lots of work which could benefit greatly from IT knowledge, so I suggest you continue to poke around in the editors (the one on osm.org, iD, is also very beginner friendly), make some edits and refer to the wiki for details on tagging conventions to familiarize yourself with the (admittedly a little unorthodox) OSM way of GIS.
Happy mapping!
