For starters, you don't have any IP for your untrust interface, nor any routing configured. That would certainly cause traffic to go nowhere.
Beyond that, you've got a funky combination of using L3 and L2 interface configurations, which is a result of Junos letting you do things in more than one way but not preventing you from overlapping them and having silly results.
You need a vlan interface for your untrust side, either from the "default" vlan or a new vlan that you define for untrust, and you need to set up your L3 interface with an IP and appropriate routing.
You're assigning VLAN membership in multiple places. Again, this is one of those kind of stupid things that Junos does... I suggest you pick one -- either assign VLAN memberships under the interface configuration, or assign interfaces under the VLAN configuration -- but NOT both. Otherwise, you're just asking for mass confusion at some point.
Assign your L3 interfaces to your security zones, not your physical (L2) interfaces, so don't do this:
security-zone trust {
host-inbound-traffic {
system-services {
all;
}
protocols {
all;
}
}
interfaces {
vlan.0;
ge-0/0/2.0;
}
}
Take the ge-0/0/2.0 out of there...
There is a learning curve from ScreenOS to Junos, and Junos really *does* have a lot of stupid things that it does and it won't warn you if you do something odd in a lot of cases.
Writing a complete config for you is a bit much to ask of a forum support group, but we can help with individual questions as you run into them.