The presser foot pressure is DEFINITELY adjustable on your Featherweight. Turn the adjustment screw clockwise for more presser foot pressure and counter-clockwise for less.
As far as the taut sewing technique, you don't want to pull on the fabric in such a way that will complete with allowing the machine to feed the material.
Threads Magazine has a Great "How-To" article in PDF format called "Drivers' Ed for Sewing Machines". It explains the taut sewing technique very well and even has photos to help. It's free.
Do you have a manual for your featherweight? It actually covers much of this. Here is a link to a free manual for your machine:
As a general rule, the heavier fabrics are sewn with a longer stitch, and lighter weight materials are sewn with a shorter stitch.