"Does that mean that I cannot use patch mode if want to use more than 1 patch in my sequencer at one time"

Yes. All sequencers are like that in one form/version/variation or another.

"> i.e. have to use performance mode & select a different channel no. for each sound I want to use simulataneously please?"

Yes. Is there *any* sequencer that can address multiple instruments playing different lines on the same channel in the same synth?

"Otherwise presume will have to continue to record each MIDI channel to audio in order to play the next MIDI sound?"

Yes. But all sequencers work this way. These questions puzzle me a little bit.

Check out Roland's Supplemental Notes for all this basic information. They're pretty clear.