I had BIAB about 20 years ago and have just come back to it with BIAB 2017 - Wow! it got a whole lot more complex over those years.

Some Newbie questions if I may, even if you just point me to the correct tutorial.

I want to step edit adding a melody. I've found I can draw notes onto the piano roll, but this is going to take forever ...
1. Is there a quick way of typing the notes in from the keyboard (in the same way as you can enter chords into bars on the Notation screen), with default snapping to whole or half note positions?
2. The B P D etc buttons top left presumably indicate the part for which I'm entering the notes. There are 3 Gs but no M (unlike what's shown on the Help screen for this window). I think I'm entering the Melody since when I mouseover the third G it says guitar 3 track Melody. Is this correct and why doesn't the M show?
3. How do I play back my melody on its own from the piano roll? I get all the other instruments playing and so can't hear my melody. I've selected Guitar 3 on the radio button on the top row (instead of Master), but still all tracks play at once.

Any assistance gratefully received.