After playing 1.7.2 some more, I have some stories.
First, there are still strange instances of zombie aggro, and there are still instances of instant zombie respawns.
But having magically lost my double barrel shotgun (which was a bad weapon anyways) I took out my hatchet and started running around Rambo style getting kills that way. Miraculously it worked. I scored maybe 30 zombie kills with the hatchet over the course of 45 minutes. I had my legs broken once, and on two occasions their attacks made me bleed, but other than that handling the zombies was not a problem. It was in fact quite hilarious and fun.
At a hunting stand while I was axing military zombies, I ran into another survivor. Looks like he had an M14 or something, some military grade weapon at least. Either way, he didn't fire at me- I can't say for certain if he would have if I had a gun rather than an axe. I leaned left and right with a salute, trying to show my friendliness. Then the two of us chatted for a little but. I shared some cooked food with him and we went our separate ways. It was a nice meeting. But only moments after we started to leave, the zombies we killed only a minute before respawned. So naturally I axed them to death. Then I headed north, found a barn, and finally got a Winchester! I was excited, traveled through the woods a little bit, and logged off.
I would say most of the fun just came from using the hatchet. It was ridiculous fun; charging zombies head on, not bothering to sneak (just sprinting everywhere), etc.