JC:

I see you found one of the other 'Patty' threads. The metal H9 mount is a good choice, but here's the difference and it's one of your questions. With the H9 metal mount you can't use the glow template that comes with the manual. You'll have to do all the math over again. Quite the pain (not to mention waiting for the part to show up, extra expense, etc).

Question #1- Yes, you can use the glow template that comes with the manual. Yes, it looks off, because it is. Why? Look at the motor box, you'll see that the right thrust is already built into it. (One side is longer than the other.) The reason then why your seeing that it looks off is for the difference in the thrust line. Great Planes made it easy for you with the template and did the math. If you use their mount, use their template. It will come out correctly. If it was straight, the cowl wouldn't fit as the cowl also was molded with the offset in mind. With the metal mount your going to have to do the math over again to find the right thrust line so when it's mounted it will match the cowl.
This has to be done with the larger models (33% 35% 40%, etc). Because of the different engines used, and mounting techniques it's up to the builder to figure degree off set, thrust line etc to get it right. Since the BME is one of the only gas engines that can be mounted like a glow engine, your in luck! If you would have bough the DA50 for instance, you'd be doing the math right now.

Question #2 - Yes, I used the CA hinges. I cut them bigger (you can buy more hinge material at your LHS). If installed properly the CA hinges will never come out or loosen up. Since you've been in the hobby for 20 years, you should know this. Yes, other guys/gals use plastic hinges, or hinge points, etc, but the CA ones are fine for this size plane. Trust me one this one, I've put my Patty's through some very extreme maneuvers with lots of G forces. Never had a problem.

Question #3 - (Just realized I'm going back wards in the order the questions where asked..) Any way...It's not a big deal, just another expense. The Bosch cap and wire is about $22, the newer hall sensor is about $10, labor & shipping, figure another $15. CH will do the mods and have it turned around in under 2 weeks (from time you send it to the time you receive it back), but your going to spend a little under fifty bucks. I would wait and see if you have any RFI problems first before making the upgrades. (Save the money for now.)

I know this is your first gasser and you want everything perfect. I don't blame you one bit. But think about this, if you start changing a lot of things (IE: new motor mount, new upgrades to the ignition, different hinges, etc, etc.) after awhile this is going to add up and your going to find you just spent another couple hundred bucks! The only reason I had the upgrades done to my ignition was because I had a RFI problem. You may not. When wiring everything together in the plane, this is where you want to be critical and do things by the book so RFI or any thing else doesn't rear it's ugly head. All I'm suggesting is to see how things work out before you shell out more money for something that might not need fixing. (If it works, don't fix it!) We've all heard that one :-) But keep asking the questions, it's the only way your going to find out what's right and what's wrong when putting together a gas plane. Every one has different opinions, they are all good. It just depends (I guess) on how much your willing to pay.
Not to mention we all love toys (or we wouldn't be in this hobby). I have over $4K in my 33% Edge. Most of it is unnecessary, but I listened and read and got carried away. I now know when to stop and see that sometimes we don't need all the bells & whistles to have a great flying plane. Keep the questions coming!