The sus. arms react like seesaw with each other left & right,so you can't say "Independent", it's called full floating suspension,without power assistance,leaning and steering independent just like a 2 whees bike

the sus. linkage all parallel no need king pin inclination for leaning bikes should be also fine,brake also no ploblem

Yes; caster is adjustable;the bicycle kit basic dimension almost the same as motor ones but lighter the tube and plates