1.a Intersection option works like it was described in request... For multiple segment selection, you'll have to repeat command on returned pline of previous operation...
1.b Curved segments are impossible to offset with this option - result is not predictable if it's not the same as standard offset operation, but then again you can't offset just that single curved segment - you have to operate on complete pline...
Only 2.a I did understood, but it's also impossible to realize... We don't know on what segment would chamfer situation be reflected when "Complete" offset operation is chosen... Pline arcs are all treated the same way if "Bulge" are to be preserved - this can't be reflected on straight segments...
2.b When original and offset pline don't have the same number of vertices it's unpredictable how would fillet operation be performed for curved segments - preserve "Bulge" option is chosen, so this situation is refused from consideration in processing this option...
M.R.