Have you added your Project List to the header zone and your Project Task to a left zone. Could you send a picture of the screen in edit mode so it show where each web part is in each zone.
You can add both task and project list to the same web part zone.
You can edit the size by clicking the edit page and then click on the web parts drop down list and choose modify the web part.. Under appearance you can change the size.
iAlso you can increase the size of the web part zone using SharePoint designer.
Otherwise I would suggest that you add a page with a full width web part zone.