If you can say that everyone on your system (the approver included) will have InfoPath installed on their local machines, then your tasks should open in InfoPath by default. Using the browser takes a few extra steps, so hopefully you don't need to view the form in a browser.
Yes, you would use the 'Load' method to pull your data from your SmartObject back into the form.
Tim Byrne
Clarity Consulting
http://www.claritycon.com