Thank you very much for the feedback.
This is all pretty technical but I do understand what you're saying.
So basically, the project is feasible, but very difficult and requires that the developers be skilled in various discplines.
We were pretty much happy with the result except for the fact that the echo kept ruining all the conversations.
And then, echo + distortion from 1 or more users would just make the entire experience very poor.
Then we came at a cross-roads.... do we find a new developer to finish what we started? (since the others gave up).
Or, do we start over, from scratch, with a different technology.... (according to me, Google Hangout doesn't use Java, neither does Facebook chat, so why should we?)..
But I myself am more of a webdeveloper rather than programmer...
So i really appreciate your input!