The worst thing that can happen is unexpected pitching and roll on a maiden flight. The less experience the test pilot has the more precarious this becomes. This is not a put down but it sounds like you are not that experienced and maybe it would be wise to seek the help of an experienced pilot for the maiden. He could trim it for you and let you give it a go some 3 mistakes high. If it proves too much of a challenge for you he can take it back and land it. Maybe a small dent in your pride but you will still have the airplane to fly after gaining enough confidence.

Like the others have said how something will fly might surprise you even though it may appear too heavy. Years ago if you told me that a 14 ft span with a .65 would lift and fly a 46 lb all up (including payload) model I would have thought you were out of your tree.

[youtube]http://www.youtube.com/watch?v=g8xC-pE6RoA[/youtube]

Give it a shot if you lack the confidence then its no shame to ask for someone with more experience to help you test fly it.

Dennis