I have explained which problems I'm solving. I need other specific/practical problems to be able to adjust my decisions. This is the reason why I'm doing a change and waiting for a loooong time for other possible problems to rise.

Well we (Lithuanian mappers) are discussing it in pubs... I've added a lot of river/stream ways to connect water basins, this introduced duplicate names, so I'm looking for the ways to solve this. Alternative would be to remove waterway=river/stream tag altogether. Or removing name tag.
As per wiki drafts, I'm not a big fan of wiki on tags, it has a lot of conflicting and questionable information (like infamous failed natural=water+water=lake|reservoir etc.). When I'm done, then I could add something to wiki, or not :-)

What is a problem you're having with this tagging of waterway in waterbodies? Is it something more than automated QA rules?

I've already added a local (Lithuanian) rule so that streams/rivers should not have name tag when intersecting natural=water, looking at what happens and planning to extend this to landuse=reservoir.
Reason is that there is no stream/river at that point, name is not required (because lake/reservoir gives a name in this place). On the other hand stream/river vector is required to be able to calculate river basins.
This is one of "work in progress", therefore no documentation.

Reverted. name->waterway:name was done on purpose because at this point it is a reservoir, not a stream/river.

highway=construction
says that it is a construction site.
construction=trunk/primary
says that after construction is done, it will be a highway=trunk/primary road.
So it is not necessary to remove construction=xxx tag from roads which are under construction.

Here:
https://lt.wikibooks.org/wiki/Atviro_%C5%BEem%C4%97lapio_vadovas
and here:
osm.wiki/Lt:WikiProject_Lithuania

Esmė būtų ne stambūs/nestambūs, bet jei šaligatvis yra kelio dalis (nėra atskirtas fiziškai), tai tada nereikia atskiro vektoriaus.
Tarkim kiemuose šaligatviai visada yra kelio dalis.

Ar yra koks nors konkretus praktinis tikslas paišyti šaligatvius 50 centimetrų nuo greta esančio privažiavimo (highway=service)?
Lietuvoje buvom sutarę nepaišyti atskiro vektoriaus šaligatviui, jei jis nėra fiziškai atskirtas nuo kelio.
Priežastis: per daug vektorių, kurie nei į žemėlapius netelpa (tenka vis tiek išmesti šaligatvius paišant žemėlapius), ir maršrutizavime neduoda daug naudos.
https://lt.wikibooks.org/wiki/Atviro_%C5%BEem%C4%97lapio_vadovas/Redagavimas/P%C4%97s%C4%8Di%C5%B3j%C5%B3_keliai

Not all places marked as cities are cities (f.e. Grigiškės is part of Vilnius).
Dupilcate, because administrative boundaries are alerady mapped and tagged as admin boundaries (admin_level=8).
In Lithuania place=* is always a node.

Čia yra privažiavimas/pravažiavimas, tai nėra Baravyko gatvė.

Incorrect and duplicate info. Reverted.

Incorrect and duplicate info. Reverted.

Papildytos IKI žymos: shop=supermarket, pavadinimas, darbo laikas, adresas (pagal iki.lt)

Adresas Metalo 16 yra įvestas pramoniniam plotui. Vienas adresas įvedamas tik vienoje vietoje. Teritorijoje esantiems visiems adresams nereikia įvedinėti to paties adreso.

Žyma power=substation sako, kad pastatas yra pastotė. Teksto/pavadinimo „pastotė“ įvedinėti nereikia.

For me the only problem is overlapping water polygons (natural=water over natural=coastline). If either of those is removed - QA rules would be happy.
So yes, changing natural=water to natural=bay would be enough.
I'm not sure about water rendering in zoom 0..5, Peipi lake tagged natural=water is visible on the border between Estonia and Moscow (relation/1318060).

Well, if you need this newly created waterbody for some practical reason, you should fix the topology error by removing all corresponding natural coastline tags (currently natural water is overlapping natural coastline).
If you do not need need this newly created waterbody - then either you should revert the change (remove natural=water and name tags), or I could do that (no problem with that).

Hello. „Kuršių marios“ object was added only for technical purposes, that is why it did not have natural=water tag (this area was and still is covered by coastline). If such object is really needed, shouldn't natural=coastline be removed? Because currently there is a topological error - duplicate of water areas: natural=water over natural=coastline.

Ok, thank you. I will add fords then to fix topology.

Hello, how does path (way/566876368) cross the river „Žvelsa“ (twice)? Ford? Bridge?