I'm organizing my todo list like this
== today
- task 1
- task 2
- task 3
== tomorrow
- task 4
- task 5
== next week
- task 6
- task 7
etc because some blog article I read about Tadalist suggested this, and it works fine for me. If you want to move e.g. task 2 + 3 into tomorrow, you simply move tomorrow after task 1. I don't like to set up dedicated due dates because most often you won't be able to comply with them anyway...moving stuff into tomorrow / next week etc. is more simple.
Thus you maybe want to add the possibility to add descriptions (which you can move like tasks).
The pricing of Todoist ( 29$/year) sounds reasonable to me.