I haven't had time for updates (I'll try to rectify this). But in the meantime I have a few thoughts. Bear with me, as a lot has happened, and my thoughts will wander from topic to topic.
1st, much has been made of NATOs unwillingness to risk war with Russia. What nobody seems to have considered is Russia's unwillingness to risk war with NATO. I suspect this has at least something to do with Russia not striking western weapons shipments.
2nd regardless of how the Moskva sank, it's important to understand that it's combat value in this particular conflict was low. It's a huge symbolic loss and a sign of major incompetence regardless (if they really took an AShM volley, it's a failure of missile defense, if they hit a sea mine how did it even sink, if it was a technical fire then it goes to show how poorly maintained it is and how outdated the fire-fighting system is). Any major damage to the ship would have render it unrepairable regardless. The only yard that can do the work realistically is half the world away (Nikolaev's yards are rusted into disrepair beyond all reason) and the cost of repairing a 40 year old ship after major damage is staggering while its value is limited. Realistically even if it had been towed back to Sevastopol', those resources are better spent on new 22350 frigates. And I strongly suspect, had one of those frigates been in place of the Moskva, the situation would have turned out differently.
3rd Mariupol' has basically fallen. Regardless of everything else, and the slow speed notwithstanding (slow compared to what though? major urban battles take time) Russia has succeeded in taking a large-ish city with many well armed defenders using a relatively small force, and relying heavily on rebel irregulars and even (rebel) reservists. Amidst the general failures of this war it is a success and it's important to look at it and see it for what it is. A half-destroyed city, most of its inhabitants fleeing or dead, 6 weeks of heavy fighting - a success. I think this answers the question of why Russia isn't assaulting Kharkov, or Kiev. What would success look like in those cities? Russia took Kherson, Berdyansk, and Melitopol', without a fight. Anywhere it has to fight will likely look like that, even in smaller towns. Note Izyum, a small town that Ukraine chose to defend, unsuccessfully. It fell to Russian forces. The damage isn't quite as bad as Mariupol', but it's so severe that most of the population also fled, and the heavy fighting took ~a week. It's pre-war population was shy of 50 000. Mariupol' isn't an exception, it's the rule.
4th Rebel reservists and Russian forces in LDNR areas are possible signs that the rebels are spent, or at least stretched thin. In this fight so far rebel forces have done quite well for themselves, and Sparta btln in Volnovakha is the most competent infantry force from the Russia side that I've seen footage of. Granted they're an elite rebel unit, but nonetheless it's telling. Reservists did start showing up well before the fighting got bad, so they're not a reaction. But their heavy use in Mariupol', and social media reports of them taking heavy casualties (what with the lack of training and body armor) are in my opinion indicative. And Russian units redeploying to the LDNR front make sense from the strategy shift stand point, but only at first glance. If the rebels were in good shape, Russian forces should have massed at Izyum and near Gulyapole (in the south). But instead they've shown up by Severo-Donetsk, and even south-west of Donestk by Volnovakha. I suspect the rebels have exhausted much of their fighting strength in admittedly successful offensive operations, DNR forces against Mariupol' and Volnovakha, LNR forces in taking almost all of northern Lugansk region. Rebel forces have been a good resource for Russia, but this well is tapped fully if not running dry.
5th Russia isn't done. It's quite likely that we will see at the very least one more major offensive by Russia. There are few major urban areas for Ukrainian forces in the east to cling to, and despite the media campaign and some of the best PR money can buy, the Ukrainian armed forces have taken horrific losses, especially in heavy equipment. Ukraine is certainly able to keep fighting, and a whole slew of new infantry brigades with western-donated weapons have been formed in western Ukraine, but the primary stockpile of artillery, IFVs, MBTs, is severely depleted. Russia continues to control the skies. It's quite possible, likely even, that Russia can succeed in this upcoming offensive. Russia will likely not be able to (my money is they won't even try) take Zaporozhye or Dnepropetrovsk. I suspect an assault on Kharkov won't happen either, unless Russia opts for a long war, with a serious domestic mobilization effort. In all likelihood we will see either a fighting withdrawal, or an encirclement and destruction of Ukrainian forces in the east (possibly both). Withdrawing on roads when the enemy has air superiority is not likely to look pretty. We have footage of Ukrainian forces from around Mariupol' that tried to retreat towards Zaporozhye to attest to that. We will probably see another Mariupol'/Volnovakha style battle around the Slavyank-Kramatorsk urban sprawl.
