I think you can use the Hierarchy and/or HierarchyBelongsTo function to create hierarchy tables for your five dimension tables. Those tables can be linked directly to your MasterLink table.
You can use the Qlikview Components library to quickly create link tables. I'd try using this library to create your MasterLink table. See the LinkTable.qvw document in the Examples folder after you've extracted the files from the qvc-7.zip download.