Meow, meow!
Yes. You could use mailgun.com for example for sending mails. You get 10K free I believe and it’s easy to setup
For the hostname aka domain change it to your own, likewise with passwords for each installed service. Like the docs say, most services are additional and not required ;-)
Kbin is super much in alpha dev still! Perhpas tryout Lemmy, thats a little further along (our instance is on https://u.fail)
Awesome! <3 Merci!