IMPDP - load data between to part tables - exchange part

Oracle DB: 11.2.0.4

Linux: 6

INFO.: We have 250 daily date RANGE partition tables as follows. These are huge partitions  - 2.5 to  4 GB  each.

               Table A has 90 partition loaded and 160 empty partitions.

               Table B has 160 partitions that I need to load into Table A

Question 1: is it possible to exchange partition between two same structure partition table from Table A to Table B.

               For example: Can we exchange partition P_20150901 from Table A to  partition P_20150901 with Table B?

Question 2:  can I import via impdp the remaining 160 partitions in Table A without corrupting existing 90 partitions from table B?  Note: I can import 30 days at at time.  is there a way to avoid archived logs for this operation only?