When creating Milestones there should be a way set one milestone to the “default” milestone. Then entering Test Plans and Test Runs it would be select the “default” milestone automatically.
When entering Test runs in a project where there is only one Test Suite it should not ask you to select the Test Suite, since there is only one Test Suite to choose from. It should skip that and select the single Test Suite by default.
You should be able to Import Test Runs. Give it a Test Run Name, Milestone, Description, Assigned Name and Test Suite(s). The same XML syntax like importing Cases works really well. This would be a huge time saver.