Welcome on the forum! We’re not aware of anyone who has taken this path yet of external providers, so it will be interesting to see how that works out.
Whether you go for a ‘managed’ solution or go for self-hosting, that depends a bit on your existing skills and/or your availability & interest to learn. Typically, ‘managed’ solutions are easier (the hoster manages the Nextcloud installation for you) but I believe often do not allow just any application to install.
That’s a good one. What is supported by the provider sometimes is a bit opaque (not transparent). The best way is to see if you have ‘admin access’ and/or can ‘install any app’. And if that’s not clear, the only way would be to contact the provider.
I found it interesting to read some of the hosting-related threads on the Nextcloud forum. Apparently managed Nextcloud on IONOS is to be avoided. Cloudamo seems to allow you to install any app. Cloud Home Lab (who also promoted themselves) on the forum isn’t clear about this - I’ve sent them a message to ask (as they’re Dutch and I’m curious to know myself).
Please do share your experience - I’m sure it’ll be useful for other AntennaPod users!