“Expanded goals”?
Every regular unit in the Russian Army has already been identified in Ukraine. They have even drawn garrison units from every border, including those assigned to, say, hold down Dagestan or watch the Georgian border.
If your army cant hold ground it cant “kick butt”, because it cant attack in any significant way. It leaves the enemy with the initiative, and the ability to, say, cut your supply lines, as the Ukrainians did. As in cutting the main railroad route into Luhansk/Donets (from Belgorod, the MSR), and putting the other under fire. There is only the line from Crimea fully functional, and its trucks from there.
As for the rest, excuses. Bureaucratic bumpf.
Not all units were involved for sure.
Regarding the rest there is some truth it your points because nobody anticipated such level of NATO involvement plus the willingness of Ze regime to kill tens of thousands of his troops for even minor goals. The kill ratio is 10 to 30 to 1 though and it can’t be sustained. They now have a couple weeks until bad weather to try a couple offensves. Then their advantage in manpower is going to be of little help.