sql problem with multiple linked tables
For your SUM issue, please see this article for a detailed description of Oracle solutions that may be helpful --> https://community.oracle.com/thread/2137764?tstart=0

For the LISTAGG issue with duplicate values and values from other columns, check out this article for some solutions that may work for your need --> https://stackoverflow.com/questions/11510870/listagg-in-oracle-to-return-distinct-values

With some quick reading and not being an Oracle SQL guy, this seems as if there are a couple things in these that may help but I cannot easily provide an example query for you to use at the current moment unfortunately with this table data examples you provided.

Hopefully this will be helpful or point you in the right direction for the two issues I see with what results you get and what results you need.