Work on modifying TaskZilla for our company's needs is going well and I've also filed some fixes/addons in the mail Bugzilla. The most part which lies ahead consists of just renaming terms in Bugzilla, such as "Product" to "Team" and so on. Shouldn't be a hard task.
ATM there is just one not so easy wish: Cummulate all times (Worked hours, remaining hours, estimated hours, original estimated) of depended bugs/task into the parent. But there are a few things left to discuss about this, so I'll let this rest for now.