Will 2Do show iCal events and tasks together in the same list?

No. You cannot mix tasks with calendar events in the same list. Events and tasks are fundamentally different types.

2Do does show your calendar events alongside your tasks, in a dedicated space rather than mixed in:

• iPad — use the right calendar/editor pane when it is visible. In a narrow iPad window, use the same swipe-left Utility Panel gesture as iPhone.
• iPhone — swipe the task list left to reveal the Utility Panel, then tap the Calendar Events button in the bottom toolbar next to Nearby/location.
• Mac — 2Do shows a read-only Calendar Events day bar pinned above the task list: above Today by default, or across your other lists too if you turn that on. That day's appointments sit right above its tasks. See Calendar Events in Lists.