You just dumped a pile of Russian propaganda that Russian state TV repeats about hundred times a day. Nothing in your post and that propaganda has any relation to the case of these bodies on Bucha streets.

The bodies weren't lying on each and every street. They were mostly in an area of Vokzalnaya street and Yablunska street crossing. The mayor probably didn't know about those bodies at the time and even if he knew it doesn't matter really - during Great Patriotic War the Soviet people lost close to 30M lives, yet still were similarly happy on kicking foreign invaders out of their towns.

The bodies concentrated near that major Vokzalnaya and Yablunksa street crossing match that typical USSR/Russian pattern of armored convoys moving through the cities using major streets toward the center of city and shooting anything that sticks out on their way. Prague, Baku, Groznyy. They tried to do similarly, yet failed, in Kiev, Harkov and other Ukrainian cities. Yablunska is the major street controlling the northern side of the Bucha river and Vokzalnaya street is the major street that leads right to the center of the city with its central railway station. The cyclist video showing Russian convoys aligned along these 2 streets shooting at everything that moves firmly confirms that Russians were following exactly that pattern there too. Now why bodies are concentrated at that location? As evidenced by the cyclist video the convoys made a stop there. It is pure statistics - the longer convoy stays at one place the more chance that the people would appear while the convoy is there, and thus more bodies. How long the convoy was stopped there for - one can get some idea of that by those Russian military rations packaging strewn all around there.

Did Ukrainians kill some collaborators/traitors and brought their bodies to that street crossing to hide them among the bodies of the people killed by Russians? While theoretically it is possible, that just wouldn't make sense. The point of killing collaborators/traitors is to send a message.

>It's also clear that Ukrainian forces sometimes are willing to kill surrendered people with white armbands, after tying their hands too [3]

Anybody expecting Ukrainian forces to strictly follow Geneva convention wrt. Russian soldiers is just not aware of the reality there. Russian soldiers are destroying the cities and raping and killing civilians - while it would be great if Ukrainians still followed Geneva wrt. those Russian soldiers, it is pretty unrealistic to expect them to do that always. In your specific video the guys say "marauders", and one can see some civilian property packed on the armored carrier (and it isn't an exception - there is tremendous amount of video/audio evidence of marauding Russian forces). Right now in Ukraine, just like in 1941-45 in USSR, the crime of marauding is punishable by shooting on the spot.

Even if we drop the marauding consideration, that war in general is happening outside of Geneva conventions. Putin in his war speech on Feb 24 declared ethnical cleansing and genocide of Ukrainians as the major goals of the war thus from the very beginning denying Geneva protections to the Russian forces carrying out that genocidal war and making them immediately guilty of those war crimes the moment they cross Ukrainian border or take participation in any other way. The perpetrators of war crimes aren't afforded Geneva protections. In particular it is de-facto an official policy of Ukraine right now, and that has been several times mentioned on Ukrainian TV, of not taking POW Russian operators of artillery and MLRS systems (ie. Grad/Smerch/Tornado) because of massive indiscriminate shelling by those forces of Ukrainian cities.