No idea how EzUHF is programmed, so can't really explain what's possible
But it seems weird, that you wasn't able to use channel 8.
I haven't looked into the issue with 2 I2C connected at the same time. For some reason the data from BMP085 gets "corrupted". Your readings are way off
Try to give it a go with MPU6050 disconnected, you should get a lot better readings from the pressure-sensor.
My MPU6050 is mounted in a plane atm, so I wasn't able to use it at the test-bench last time I updated the code.
Your RSSI and Link quality looks a bit weird. By any chance you have configured it to use both normal analog RSSI and EzUHF RSSI? That would explain the behaviour.
This must be set to 0 when you use PPM for RSSI and Link quality (will add a comment in next update)
// Show RSSI/2. battery or analog sensor
// 1 = show RSSI
// 0 = Don't show
#define SHOW_RSSI 0