Will the press-in crust in Amanda's peach tart work for pumpkin pie? What if I use melted coconut oil instead of canola and/or olive oil?

Did you want to use the crust in a regular pie pan? It may not be enough to form a traditional pie shell. Or did you want to put the pumpkin pie filling in a tart pan? You may have too much filling for a tart shell

I think the crust should work fine with a pumpkin pie, as long as your baking time is long enough. In Amanda's recipe, it calls for 35 minutes at 425. If your pumpkin pie recipe calls for significantly shorter time, I would par-bake.

You could certainly use melted coconut oil--one person remarked in the comments section that they had done just that and gotten great results. Conversely, there's a great coconut oil-based pie dough on the site: http://www.food52.com/recipes/19559_perfect_vegan_pie_crust