1- overloadable with a buffered guitar signal, need a mixer or other level box beforehand to avoid clipping (boss LS-2? EHX LPB1?)
2- Works best out of a mixer, so line level.
3- 500K ohms.
4- line level.
5- 10k ohms? iunno but the input/output impedances are in the manual. Same as most pedals output impedances.

The tracks all play simultaneously, you can’t step through them one by one. They’re all synced to either an internal clock or a midi clock, and are all the same length.

you ever use a tascam multitracker? that’s the closest I can relate it to – like, you can switch the volume of each loop on the fly or fade in/out individual parts of the loops, but you can’t set the start points at “when loop 1 finishes, go to loop 2, and then trigger loop 3 to start on beat 3 of loop 2”; they’re all synchronized together as one loop but four channels of audio, pannable to two outputs. They’re all the same length, etc.