Do you think there is actually a way to tell if a save is bugged? and if it is do you need to empty the save folder or can keep the global save for the achievements? after switching from PedyTW to AnonTW and playing a couple of different versions I didn't notice anything particularly weird so I don't know if there is actually a clear sign of a bugged save.
I haven't updated my game since July, but you should be able to update a save within the game's menu. Failing that, using Baitsu Dasuto might salvage your character/achievements at the cost of ending your current run. Personally, I've been playing the same save for the past 2 or 3 years now and it works well enough.
I have to turn off banquets because some characters attending will crash my game, but I've never found them super useful in the first place. It's nice for stealing a shit ton of panties at once and raping drunk girls (because it usually takes a lot of time and sake to do it normally), but it's a pain in the ass if you're trying to flirt with them and they're too drunk to raise favor.