Yeah the notifications thing is set to default whenever you make any adjustments to your episodes and that is...wild. I'm always so nervous I'll accidentally click "yeah send notifications" when I simply just...added music or something. I'll generally not unsub from too many notifications but like...I'd follow you on twitter if I wanted this many notifications, please let it alone.
As for unsubbing--I tend not to do it, especially from very small comics, because like...it just feels like for small comics it'd ruin their entire day. Like when they have 30 followers it's like...well I guess I'm subbed to this comic for my entire life. (usually not a big deal, those comics typically only have like 20 updates and then they never update again) but I have unsubbed because content got...gross. Like usually because of sexual harassment or just...kinda a nasty vibe that comes out of no where.
For really big comics that I feel no guilt from unsubbing from, I tend to do it if they don't have a level of maturity in their writing. Like because I'm an artist, too, I really am not that impressed by art? Sounds kind of terrible to say it like that, but I see no purpose in making a comic if you're not doing it to tell me a story. You'd be better suited just making illustrations. Yet, there's a lot of comics that are very pretty, and also pretty boring. Or, they're pretty, but also pretty poorly written. Also things like bad font and poor grammar and spelling just take me completely out of the comic (novels as well), and I have no patience for it.
There's also been...some comics...I have un-followed because they were dicks on twitter but they're not on Tapas so that probably doesn't count.