Usually, I’d aim for the cloud environments for public resources (serving more than like 20 people), as the traffic won’t be hitting your home network.
Additionally, selfhosting a public service like Lemmy on your home environment probably wouldn’t have the same uptime or reliability, as I only have one strong ISP signal, and no backup generator.
However, pricing wise, selfhosting at home is much cheaper for the processing power you get.
No, definitely not. I don’t want my home network to be in any way accessible to the public. No matter how secure you think your network is.