Inveniō is Latin for "I discover", "I find" or "I come upon". See Wikitionary.
It's called a Macron. It is used to mark a long vowel.
Inveniō is constantly looking to add new services. Hopefully it'll be added soon.
Because of the macron above the "o", the URL is classed as an Internationalized domain name. Because IDN characters can look similar to other IDN characters, they are converted in to Punycode. The funny looking Punycode URL will still work if you paste it in the browser. Alternatively you can also use http://invenio.video.
No, completely independent.