I'm running into the same problems.
I used the To-Do tasks on the right side of my outlook to organize my day and now I have to figure out something completely new. Also, the reminders that I set for myself in the new 'To Do' App don't notify me when I open Outlook.
Overall, I like the new feel of outlook, but the functionality is not there for me.
The old teams was much more user friendly and easier to lay out for busy individuals. The New outlook feels watered down and missing a ton of what made Outlook so great.
Really sad if this is the finished product.
Edit: forgot to add, that when I complete a task on a flagged email, in the old outlook, that email would not be flagged anymore, now the email remains flagged until I go in and manually check the email off as completed, even though the task has already been completed.
ALSO, I LOVED the fact that I could right click any task in the old outlook, click 'Find all Related messages' and it would pull everything in that conversation. I've lost so much time after switching having to hunt down email threads.