As per https://en.wikipedia.org/wiki/Kiseljak is a municipality, but the administrative boundary is missing.

Two admin level 7 boundaries (= Eurostat LAU-2) for Fojnica and Kisejak missing in Central Bosnia County (level 5)?

This "rectangle" is not assigned on admin level 8 to any of the three surrounding cities, Fehrberlin (unlikely) Kremmen (unlikely, different level 6) or Neuruppin (likely)?
Can also be seen in https://osm.wno-edv-service.de/boundaries/ when selecting the three cities.

relation/3463793 is DUPE to relation/342556 (both for Villafranca de Córdoba, both admin-level 8), causing havoc! Please delete relation/3463793

According to http://en.wikipedia.org/wiki/Usora_Municipality and BA national statistics, Usora is a new municipality extracted from both Doboj and Tesanj and as such update of the administrative boundary level 7 would be necessary for the three municipalities.

https://en.wikipedia.org/wiki/Hiiu_Parish says:
Hiiu Parish was established by merging the town of Kärdla [OSM relation/351941] (former urban municipality) and Kõrgessaare Parish [350685] after the municipal elections held on 20 October 2013.
Hiiu is also refered by Eurostats as NUTS3:EE004, LAU1:0039, LAU2:0204
Being a user, not a mapper, I would appreciate if someone could merge the two.

According to https://en.wikipedia.org/wiki/Ranilug Ranilug or Ranillug is a town and municipality located in the District of Gjilan of Kosovo.

As the Serbian government has stopped to publish statistics for the region and OSM has the data as Republic of Kosovo, it would be helpful to have the proper administrative boundaries.

OSRM zeigt bspw. nach Hamburg keine Verbindung über den Hindenburgdamm an, dafür doppelte Fährverbindung via Dänemark. Ich nehme an, dass der Übergang auf den Autozug nicht eingerichtet ist. Dies sollte nach meinem Verständnis analog einer Fähre funktionieren?
Ich bin aber kein Kartenprofi :-]

Incorrect admin-boundary level 8 on relation/4012562

According to OSM Boundaries https://osm.wno-edv-service.de/boundaries/
relation/153832 is the missing area represented by Quedlinburg. Which 4012562 is part of.

Please add english name "Llocnou de la Corona" to relation/347623 as referenced by Wikipedia and Eurostat.
http://ec.europa.eu/eurostat/web/nuts/local-administrative-units (NUTS3-LAU2: ES523-46152)
https://en.wikipedia.org/wiki/Llocnou_de_la_Corona