I have done lots of testing with engines out and with different size engines and out thrust will keep your plane from making the big yaw and roll if an engine inadvertently quits. I can literally keep doing acro with one engine out.

Go to the twin forun and do some research. The tri-engine Savoia-Marchetti, .91FS in nose and 2 .61FS in outboards, lost 1 outboard and crashed. The twin Sig Somethin' Extra lost 1 engine and crashed. I hate to see nice planes destroyed. That's the reason I got started on the out thrust experiments. You might not like the way it looks, but it dang sure works.

As for designing a twin, probably the most reliaboe design from a handling standpoint would be a pusher-puller, either on a long fuselage or with tail booms. The nest best would be a twin fuselage design. The fuselage channels the air flow more straight aft so you tend to get less yaw with an engine out. Finally would be 2 nacelles, which is the most common design.

If you are a very experienced pilot and know how to use your left hand on the rudder, build then straight ahead. Make sure you have enough power with 1 engine to overcome the drag of full rudder and still maintain level flight. If you are under powered, you may be in trouble.

From my experience, you need engine reliability first above all else. I get the feeling that many inexperienced pilots start off running their engines pretty well, slightly rich, and they don't have much trouble. After several successful flights, they crank on the needle a little for some more performance and one engine may quit on a partial tank. This is where they get into trouble.

In the final analysis, it's pay your money and take your chances.