Hi and welcome!
- Yes, you should request exult.info. You can test it by adding an entry to your /etc/hosts file, e.g. 212.85.158.4 exult.info to make your browser believe exult.info already points at TuxFamily.
- Technically, you can leverage your TuxFamily SSH access to update your files any way you want... but in practice, giving your TuxFamily SSH access to a third-party sounds quite dangerous. Fiddling with a separate user and Unix permissions is possible but remains error-prone. I see two main approaches: a TuxFamily cron job that regularly checks whether it should rebuild your site, or a custom web page with authentication to reproduce that upload-unzip-done mechanism you described.
- I confirm installing phpBB should work. Just beware of spam.
- once your web area is created, you can use it. The TLS certificate is created and installed automagically, BUT it happens at night, so your web area will be TLS-less for the first day of its life.
By the way, most questions about TuxFamily have their answers on our FAQ, e.g. https://faq.tuxfamily.org/WebArea/En#Ho … 2FHTTPS.3F -- feel free to have a look (and you can even improve it if you want).