Hawker,
Certainly your story causes me to really appreciate 35 years of flying, without crash or injury, and having my health. I'm certain that you did not go to the effort to write what you have so I could appreciate my life, but I do anyway (even a little more now...)
It is obvious that you're looking for a little support from your peers, and who could blame you, but I'm not sure what I as a peer could do to offer support, other than some kind words, and you got them early on.
Judging from my limited knowledge of the type, the aircraft you were flying was not intended or built to comply with prevailing design requirements for certified aircraft. As we live in a free world, it is generally permitted to build (and test fly) aircraft which do not meet the design requirements. In the countries I know, the aircraft in such cases is required to display a warning that it does not meet the certification requirements, and there are a lot of those requirements. One of them defines a maximum stall speed (or, to some degree, how it's going to glide), and lesser known, pilot visibility (or, what you're going to be able to see when the liquid goes from where it is supposed to be, to your windshield). The aircraft may still meet these requirements, but you are on your own to make this determination, the authority has not done that for you.
Tempting as it is to get into these fast little glass backward foambuilts, there are some downsides, of which you are now all too well aware. It sounds like the "test flight" you undertook, was not so much a purposeful investigation of a particular aspect of flying qualities, for a serious aviation manufacturing team, as it was a test of your willingness to do a favour for an aircraft owner/builder, who for what ever reason would not do the flight himself. I have no idea the terms of the flight authority you flew under, but somewhere in there I'm sure that there was a message reminding you that to some degree, you were on your own. Regrettably you have a much more clear idea of what that really meant. Even after your accident, it's not going to change. The authorities of the world will still let these amature aircraft fly, and people will still fly them. We wish them the greatest safety and success, but know that someone will repeat your event, with the same, or worse consequences. It happened today 30 miles from where I live. Two people are not with us any more.
Engine failure and oil on the windshield are not nice, particularly together, been there, done that, but the wise engineers at Cessna provided enough windshield that I could still see out to land safely, and I did, on a runway no less! When I was asked (more than just invited) to test fly a Quicky 2 (very much like a Dragonfly) I declined. I think that I insulted the owner, but neither he, or the Q2 are with us any more. I decided right!
We each have our personal limits. To some degree, they will be governed by the motto: "If your life bores you, risk it". My personal limits are based on a life I love, so I don't risk it. I test fly many aircraft, but they are all aircraft which were eligible for a C of A before the modification I am testing. My test flights are all done in accordance with a Transport Canada accepted test flight plan. Is that a guarantee, no, but it's a "check and balance" in my favour. I'm not knocking amateur built aircraft, many are excellent, but my personal limit is now "the tried and true". I'd be silly to say that I'll never be hurt in a plane, but here's hoping not, and I'm still following my plan.
I'm not sure what we can do for you here. I'm sure everyone would like to help you out, but speaking personally, I don't see a path to do anything other than write something supportive. Do also know that other searchable postings on the internet really do contradict what you have said in your first post. The truth can be seen in different ways by different people, but to get the best support, give the best truth…
My best advice, is join in, enjoy the PPRuNe group, share your WISDOM, offer ADVICE when you think that you can help a less experienced pilot, and otherwise find a path in your new life, where others can come along side, and meet you on common terms. There are lots of good people here (and a few who lack tact for time to time) and there's a lot to share. Concentrate on what you have to share, not what you can get. You will be amazed what you will get, when you share what you've got.
Hasty recovery,
Pilot DAR