I usually put the handle in the middle and set the arrow rest just above my hand. I make the handle a little long so the arrow rest is in the center of the of the bow with enough room for my hand under the rest. Some bowyers make one limb longer than the other to accommodate the arrow rest - to make the rest in exact the center of the of the bow.
I usually make my handle fade from 1" wide (and 1.5" thick) to 2" wide (and .75" thick) within the last 1.5 inches of the handle.
This is an overly simplified explanation, but I think the worst thing we could do is "nothing". It is the experience of breaking a couple bows that teach us the most. If you offset the handle and do not like it, you could shorten one of the limbs to get it back to a desired place.
If you do not want to ruin a nice piece of pecan, then build yourself another bow out of something else to test the dimensions. You could build several pine bows in the time it takes to "decide" how to proceed with the pecan.
I'm just rambling now... so I'll shut my trap.
Let us know how it is progressing and do not forget the pics. Letting the folks here "get an eye on it" will be the most helpful advice you can get.