Here is an example for your first question:
Manipulate[
Graphics[Polygon@{p1,p2,p3,p4},PlotRange->{{-10,10},{-10,10}}],
{{controls,1},{1->"p1, p2",2->"p3, p4"}},
Dynamic@Switch[controls,
1,
Row[{
Control@{{p1,{-5,-5}},{-10,-10},{10,10}},
Control@{{p2,{5,-5}},{-10,-10},{10,10}}
},Spacer@20],
2,
Row[{
Control@{{p3,{5,5}},{-10,-10},{10,10}},
Control@{{p4,{-5,5}},{-10,-10},{10,10}}
},Spacer@20]
],
AppearanceElements->None
]
