I would invest some time to learn at least a little bit of SQL if I was you.
The most obvious benefit to report writing imo is that you can make commands that only pull back the data that you want at source. This will benefit performance and will give you an easier ride with some of the more complicated reports.
Looking at the relationship map that you have wrote you must know what join types are it wouldn't be such a great task to learn to apply these principles in SQL.