OK.. for the first time I can agree with all of your points. The last point is quite important. Even if Russian uses tactical nukes, it will not result in Russia winning the war. Ukraine has more than one million soldiers in active duty right now and they are well distributed across the 1,300 km long frontline. Using one or two tactical weapons to destroy concentrations of Ukrainian troops will not have an impact of the Ukrainian Armed forces to continue fighting. So in the end, for Russia it will cause more harm compared to good since their remaining allies will desert them.
There is a surprise visit of President Biden to Ukarine 3 days back just to show solidarity. US president visiting Kyiv is an indication that it's a safe city. While Chinese foreign minister is meeting Russian president in Moscow. When two big powers are standing opposite to each other, there is a rare chance of cease fire. One year of conflict is about to complete and still we have no clue when this will end.