Lessons Learned:
0) As someone pointed out to me before the match, as the grey player in the lobby I don't need to avoid being an active liability to win the match, I just need to not throw hard enough that the rest of the team can't carry.
1) Zoom out periodically to check whether I have any lost and idle units where I don't expect them. My second group of scorchers was dead weight for the entire game.
2) Check the pathing map before skirmishing with vehicles on rough terrain.
3) "Fire Towards Enemy" badgers lose badly at attrition to other artillery. During the period when I was actively micro-managing my badgers, I traded away about twenty of them and they killed a single metal extractor in exchange and nothing else. I blame this half on the micro mistakes below and half on just poor spacing.
4) Patrolling badgers stop to fire, which increases their vulnerability to artillery.
5) Repeat move badgers can avoid the stop to fire problem, but it's still not a good tactic because it gives away the ability to retreat them promptly. They will automatically return to the bad positions.
6) Attack move or patrolling scorchers on low health will suicide into buildings to kill them quicker. I got one scorcher into the enemy back line uncontested and promptly lost it like this as soon as my attention went elsewhere.
7) Area guard, given to a group, means "split up and guard individual units in the area, moving on to new ones as old ones are destroyed". It does not mean "Automatically respond to any threat against a friendly unit in the area". I had several Crashers for half the game that were guarding useless targets when I thought they should be acting as unsupervised mobile defenders.
8) My scorcher raids were collectively fine, but over half of them failed. Often, their most valuable contribution was IDing enemy targets for allied artillery, and that could have been done without driving scorchers into contact range of things they couldn't kill. I wasn't using large enough groups to bully through a layer of serious defenses and in particular should not have been trying to dive the Paladin. The one raid that got behind the enemy front uncontested and killed two Merlins mostly made up for all the bad decisions on the other scorcher raids; that's apparently where the Decorated Veteran award came from.
9) Alternative plans I should have considered, but didn't, were scouting with Darts while building up for larger Scorcher raids, using Ravagers in the same role, and escalating past Badgers to Impalers.
10) Luclucaa wanted me to reclaim my advanced geo during the endgame, but I didn't figure out why during the match and didn't act on it. Apparently, it became an explosion hazard to that part of our line while I was paying attention to the other side of the map, but luckily the team was able to defend it long enough for the game to end.
11) My commander spent a lot of time idle in the late game because I didn't know what to do with it. An area repair command covering a large chunk of our back line would have been an equally safe way to idle it, but somewhat more productive.

Lovin' the self-reflection.

Just watched through to the end and you did a really nice job with those scorchers! Just be careful of the exploding bits of your foes -- you lost most of your units to a combo of commander and factory dying at the same time. Try to only use the minimum units when finishing a factory off. It's a little dance sometimes.

Galamesh
The more general point you imply between your tips on how not to use Badgers is that if the Badgers lay a minefield along an important section of the front and the enemy team doesn't lose any units to it, it's a sign the Badgers did their area denial job. I'm aware of the line-fire method and used it sometimes, but using the Fire Towards Enemy state and creeping the Badgers forwards had roughly the same effect.

The Patrol command was specifically an attempt to keep the Badgers in the field vs. Impalers. Manual movement did the trick with enough attention, but my attempts to automate the dodging all failed.

Also, I never had 20 Badgers lined up at once. I lost and replaced some.

chaplol
I was unaware that I should be planning to cover any particular section of front from the first plop, and one of my comparative strengths was a willingness to shift between fronts and attack across the mid-map seam. I started where I did to make sure my team collected all the rear mexes promptly.

Regarding that particular loss of raiders, I still don't have a good feel for how large explosions are. Given that, in retrospect, going for the idle factory at all was a mistake. Same with the stunned Paladin.

@Vorpalkitty
Lesson 1 was not about having Scorchers instead of other units. It was about entirely forgetting that I had the Scorchers available. I had plenty of opportunities to use that group after my Badger phase and simply didn't.