When you record on a pattern, it is cleared. There’s no overdub that I am aware of, but you can play on top of it and between notes if a voice is free.
I’m not sure what you mean, but it’s just a progress bar. It shows how far along through the sequence - duration when unclocked, step when clocked. If you enable looping, it will loop. A manual restart is optional. Earthsea can be a looper, an appagiator, or both.
Both have their quirks. Earthsea doesn’t keep a clock. On a clock pulse it just plays back the notes in order on each pulse. Without a clock, the timing of the sequence is only as accurate as you are. The sequence ends when you end record or hit play, so that has to be part of your performance timing. This can be tricky when performing with looping against other things that are clocked. It depends on what you’re doing. The clock doesn’t have to be regular, again there is no internal clock, so there’s no lag for tempo sensing. It just spits out notes on triggers.
Earthsea is mapped to fourths and semitones. Read the manual for the original Earthsea. There’s an Ansible Earthsea manual image further up in this post. Keep in mind there are no shape runes, and there are no plans for adding shape runes, so you can ignore those parts of the original manual.
Someone else can answer here, I’m away from my modular at the moment. I’m not sure how notes are prioritzed per voice when multiple are played.
He should! 