Kind of a loaded question but if you want to play any PDGA events that are A-tier or higher you have to be a member. If you plan on playing 5 or more events in a year it's definitely worth it as you will save $50+ on the entry fees by being a member.
The magazine subscription is extra here. If you value getting ratings, access to the forums and possibly advancing the sport go ahead and register. You can get a disc if you pay for it. The price is ok.
Flat shots need running on the center line of the tee and planting each step on the center line. Anhyzer needs running from rear right to front left with the plant step hitting the ground to the left of the line you're running on. Hyzer is the mirror of that.