I just gotta say this: "Microsoft Project®" is king of that hill – and for very good reasons." It is excellent at managing inter-task dependencies. The product was born out of a set of Microsoft Excel macros that Microsoft Corporation was using for its own purposes ... and, it shows. I've never found any software product in the open-source ...
within my remote Scrum application I have integrated very simple assessments - for the ProductBacklogItems as well as for the tasks:
A) the risk is a combination of:
1.) complexity: value[1,2,3]
2.) innovation: value[1,2,3]
B) dependencies are in both directions:
1.) how much do others depend on this task: value[1,2,3]
2.) how much does this task depend on ...