How about creating an individual Task-List foreach user (or rather let them create it by themselfes).
You could also create an template from your preferred tasklist-configuration.
The only other option to personalize a list (other than item level permissions) are the views which can be customized by each with contribute permission.
Update for questions in comments
I actually testet this and you don't need to modify the .stp since SharePoint is quite smart when adding a template.
But since i wrote this already here's a newbe tutorial.
How to get a ContentType's ID via the UI:
Go to Site Settings > Web Designer Galleries > Site content types
Klick your desired ContentType
Look at the URL and find something like
Thats the ContentType's ID.
The template I've created does not have the same content type ID as the original list's content type's ID?:
Yes. If you add a ContentType to a list, the ContentType is only the base for a new ContentType created explicitly for the list. This is necessary due to the fact that you can modify a ContentType in a list without any inpact on the other references of this ContentType.
You can validate this by adding the contenttype to the list and view it in the list settings.
The ContentType you started with is the parent. You can also have a look at the url again.
The generated id starts exactly like its parent but there is a postfix generated for this unique ContentType.
How to modify a .stp:
Here's some reference :
What needs to be changed:
Search for all references of your ContentType ID and trimm the part that is not the parent ContentType.