No worries about spamming the forum, we’re here to help and the more questions that are asked the more information we can push out there 🙂
WooTickets builds on WooCommerce, so any restrictions affecting WooCommerce itself will effectively be inherited by WooTickets. So the inability to use WooCommerce on a multisite installation for instance isn’t something I was actually aware of, but if that’s the case then yes you would very likely hit some problems here.
In terms of extending WooTickets, there are action and filter hooks throughout our code and other hooks provided by WordPress itself can be leveraged to change WooTickets’ behaviour, too. You are limited only by your imagination!