Fraza
My breeding pairs of javas are not housed with other finches. They have their own 6 foot flight (just finally put up). So I am not sure I can be of help with mixing them with other species.
I will be housing them only with their own species.
I have handfed 3 babies all in the same clutch and all day long they sit on my head (my hat so they dont poop on me), peck about my desk and ride the tops of my fingers while I type on my work computer.
My work days have never been more enjoyable, and I will not give up these 3 kids for the world!
These are large finches with HUGE beaks able to hull seeds, my other species wont even attempt, so you would have to gauge the personality of your Javas. They are strong birds.
I'm certainly no expert on Javas, I'm new to them myself. Keep in mind, your aviary is only big enough to fit so many birds. ;)