The icon will show the color of the project. This way you can identify the project. Beside this, there is currently no other way.

Technically this will not be easy. I will search for a solution

I'm not sure about this, but i think that all actions of a project should be put on the next list. But i see the point, that maybe an action depends on another one and thus can only be done when the dependend action has been done already.

Can you please tell me which synchronizer you want to use? So i can help you with configuring.

I agree that the current implementation is not consistent and may confuse the user. Though, the current implementation is the way i like the most :-) I will think about a consistent implementation. Thank you for your suggestion.

You can already create tasks with a recurring action in patterns like: every second week.

Just select: Recurring regular, Weekly and then enter Every '2' week at 'Monday'. To create an action every other week at monday.

I am planing to implement an auto creation for for birthday related actions.

As a work around, you could create yearly birthday actions like:
- Create a recurring action
- Set the period base to monthly
- Create the action every "12" month at the date of the birthday
- Set the start date to the date of the last birthday

I have not tested this, but it could work :-)