John,
If you've used the proper construction techniques, the Easy Riser is a marvelous aircraft. I've had friends soar them many thousands of feet high with no problems at all. (Dave Ductor please call John.) There are ways to tighten up fabric using heat and chemicals, although I couldn't advise you there. I suggest you email some of the people at the ESA
http://esoaring.com/officers.htm, most of them have experience with tightening fabric on airframes and all would be more than happy to point you to the experts.
If I had built your ship, and had no experience, I would seek out a local hang glider pilot to help me learn and, in particular, man the nose rope. Then go to a nice little hill or dune that I've
staked out with streamers everywhere, and with a smooth breeze of about 15 mph ON YOUR ANEMOMETER, practice flying the crest with your friend manning the nose rope just to help you with pitch. You will figure the rudders out pretty quickly, so there is no need for a side rope.
The wind will help you maneuver and land because you have rudders, you lucky dog. You will have much more control authority than any rogallo-type hang glider.
After an hour or so of this, your confidence will be way up and you will be good to go on low flights and start having fun. Practice. Practice. Practice until you are making the correct responses without thinking, then gradually move higher (10-15 feet).
Any divergent tendencies from design errors will likely reveal themselves as you fly faster. I would try the nose rope again in stronger winds, again on a gentle hill with a shallow wind vector, just to see if the pitch becomes lighter as you speed up. If it doesn't, and you don't encounter fluttering or fabric loosening up from the top surface, I would be inclined to take it higher with out much concern.
We mention this divergent stuff to avoid a major "gotcha" common in home-building this aircraft. It does not take long to resolve the concern over divergence and once you have put it behind you, you will begin to trust your wing and enjoy it tremendously.
This is a tough aircraft with a huge record of accomplishments. People have flown them with broken ribs and ripped fabric day after day. They've hung heavy engines on them and towed banners. They are very robust. The problems usually arise from the pilot not doing proper maintenance or keeping the ship in damp storage, inviting rot or glue problems. After following your posted progress, I don't see these as issues. It's time to start flying.
All Dennis Pagen's early hang gliding books are priceless. George Worthington's
In Search of World Records has a wonderful and very detailed section on learning to fly a rigid wing.