Hi Dick,
Your correct, I'm sure John will make it right for you if you send the wing back, but I agree that the delay will be inconvenient for you because you probably bought the ARF so you could get in the air ASAP (before winter! ;-). ..... Therefore, to save you the delay time:
1. I would not worry about the soft spot in the wing sheeting. It is mostly there to hold the airfoil shape in the important 1st 25% of the wing. It does not add much strength, just a little stiffness. If it bothers you, just make a very small slit in the covering and apply a small amount of thin CA to the area then iron down the covering. Over the years I have put a few soft spots in my LE sheeting on my P-40, heavy fingers, hanger rash, etc. with no flying problems at all. I would not worry about it.
2. The small push rod between the BC and the flap horn is OK to use and the retainer clip works well, I am very surprised that it binds. Your analysis may be correct. Is there a way you can use two pliers to make a small bend in this short PR so that the angle going up to the flap horn is such that it relieves the bind? Mine works perfectly with no bind and no slop at all.
If this does not work, your ball link solution will be perfect. Don't worry about cutting into the wing. It won't hurt anything, just cut at a 45 and your surgery will barely show. To cover your scar, just use an ink line (or 1/16 trim tape) to outline a hatch, it is a military plane, and we had hatches all over them. ;-)
I used the stock short PR from the BC to the Flap horn, but used ball links and a CF PR to the EL horn. I used everything else stock on the plane, including the horns.
3. I would not bother replacing the horns, it may be more work than you need to do. A little solder should be easy. Mine were done a little more than 1/2 way around and I could not pull them apart while applying much more pressure than they will ever get in flight. They had more solder (or is it brazing?) material around them than the horns we used to get in CL kits in the distant past, (now these old ones were marginal looking!) and they held up fine. I would think that a few min. of soldering is easy and quicker than replacing the horns if they are already installed.
You will love this plane. My ARF P-40 has over 400 flights on it and it still flies great.
Good luck, and please let us know how you make out. :-)
Regards,