Pin 1 can be set to output 9V by leJOS. Take a look at...
Take a look at the native methods setADTypeById and setPowerTypeById the comments should explain what is going on.
There is currently no support in leJOS for using Pin 6 as an analog input.
What sort of device are you looking to connect? The standard analog input is effectively sampled every 2ms, do you need a higher sample rate then this?
All the best