out of commission, cant drive my dart anymore

IMHO that broken tab may be a problem it is what the eccentic washer works against when you are rotating the upper bolts to set camber and caster. So adjusting that upper bolt will be a pain without it. The alignment guy needs to know this.

It also may provide some support to prevent that eccentric washer and the bolt from moving and allowing the caster/camber setting to change when things are locked down. The torque on the bolt may be enough to keep things from moving with out that tab. I'd have it welded back on but that is going to be a logistical problem right now. Maybe the alignment shop can tack it back on with patience and little heating to the rubber; use a sopping wet rag to cool the area after each tack and take the heat out. That was done with Chevy truck lower BJ's to hold them in after the press-in holes got worn; tack, cool, tack, cool.... 3-4 tack welds and they were in for good with no issues for the new BJ.

I can't say on the lower BJ not coming loose... that is a new one on me. Heat the knuckle and let cool down a few times and see if that helps. I would not whack on it when very hot.

And, IMHO, no anti-sieze on the ball joint tapers during re-assembly.

Hope you get rested up!