Chosen Solution

Removing the center adhesive strip to remove the battery, the tweezers slipped and caught the speaker connector, pulling it away, tearing the plastic film and breaking the wiring (the broken wires can be seen under magnification). I don’t see how this can be fixed. I can re-assemble the phone but the speaker surely won’t work. Any thoughts? (Major bummer!)

From my experience fixing iPhones they have been very robust. It is very likely NOT fatal. You can remove almost every component but phone will still turn on and you can use it to some capacity. Depending on how you ripped the connector you might not have the bottom speaker, the lightning port Taptic Engine or the lower mic from what I can tell. If you just ripped the little speaker connector off then yeah, you just won’t have the speaker. I would say assemble things back together and see what doesn’t work of the things I listed. Worst case that I can think of is that you replace the ribbon cable you ripped.