With a lecture attendance record like yours? No way!
Against Ultras, do Concussive Shells work? Don't think they do but would make it simple. I'm not sure tech switching to Thor is going to work unless you scout it LONG in advance, Thors are very expensive and you need a new set of upgrades. If you've got Widow mines on the map, kite backwards over them but don't get baited and run back and lose your own units... make sure just he gets hit. Ultras work well with some Zerglings around so WM should clean up a lot of them. Just use stim, stutter step and keep Marauders at the front rather than marines to take the hits. Ultras should crumble. If you reckon they're on A move then you could be really cost effective and leave a few Marauders a bit ahead of the rest and let all your units sit still and just fire - that sacrificial marauder should buy you enough time :P That won't work on an average opponent though, only bads.
Against Protoss it's all about knowing what he's got and preventing him from knowing what you have. Not gona lie, what you need to get really good at is spotting the shimmer from an Observer, and then some great scans on his base and units should tell you what he has
Something a LOT of Terran forget is that Hellbats will absolutely destroy a pack of Zealots due to +damage against light. Also, you don't necessarily need to wait for your entire army to be attack before you snipe Colossi. If you get map vision/control and see him advancing, split your vikings off and snipe Colossi in hit and run attacks before they get to you. Would be interesting to see what your splitting is like - if you just move and then attack, you're clumped up and storms and colossi will destroy you. It's more like preparation rather than something you need to do in the heat of battle - won't need that til higher league
Colossi can be dealt with easily, it's Archons you need to worry about due to +damage against bio.