FYI, iD is a poor tool to add routes because it doesn't have function to let you readily sort members or copy existing relations.

That said, let's see if the following can be observed when adding bus routes:
1. Ensure all ways are properly split (i.e. every junction node that matters should have all connecting ways either starting or ending at it);
2. Likewise, the start / end stop position should be start / end of ways accordingly;
3. For every stop, add stops first and then platforms;
4. Add ways from start to end