Uzi's tank might be fitting too much in too small an area, the ammunition supply might run low to quick. Then again, using 6.5 Grendel miniguns instead of 7.62 NATO ones could add back some supply.
I think a heavy duty from of snow plow should be on the front of it. Make it so it can tilt up. That way it could push debris aside in the streets to help clear the way, or if the plow won't work you can tilt it up and try to climb over. And the traditional snow plow shape would also be fine for wrecking buildings.
The drive should be hybrid electric, for various tactical reasons. There are fewer linkages, and most of those are cables, meaning engine replacement could be lightning fast without complex mechanical design to accomplish it. Cheaper. The tanks could sit around with charged batteries and engines off, allowing instant response without requiring an idling engine... or producing any heat or sound signature. Handy for ambushes. Also, in an HED system both the engine and batteries would have to be disabled before the treads couldn't be powered; meaning even if the engine was taken out they could crawl a few miles out of harm's way. Which is also handy to keep your tech from falling into other hands, not to mention your crews out of enemy hands as well. Also, the HED drive could provide lots of electricity for other toys.
As for the main armament, I don't think 120mm is bad at all, only the way they are currently employing it. A shorter barreled lower velocity 120mm gun would be fine. Perhaps half the barrel length of the current tanks. But the shells it would use would be anti infantry, airbursting HE shells and flechette cannisters. A 120mm HE airburst shell put through a window can knock down all the walls of a house outwards. I might make the gun capable of using the standard high velocity NATO shells in a pinch, in case of supply problems or whatnot, but it would be intended for the shorter range anti-infantry shells.
The other way to make the gun would be some form of howitzer/mortar. Something useful for direct fire out to 400 meters or so, or indirect fire to however far. I know tricks like this haven't worked out well in the past but now... with computerized targeting it could be doable. Especially if an effective variable velocity firing technique could be used. I'm thinking about the electric-water-plasma eperiment I read about a few years ago. Put water behind the projectile, then dump a massive current through it, and it accelerates a projectile like crazy. There are some technical hurdles there, but a fluid propellant could be measured precisely for the velocity needed, and water has the side benefit of not exploding like other propellants can. And it only takes a small amount of water to do this so it saves space. You could also try railgun type launchers, but if I'm correct this uses less electricity and is a bit easier to get the physics tame enough.
A person convinced that the ends justify the memes.