The starter is probably the source of your problems. You need to look into rebuilding/repairing it, and making sure all of your electrical connections are sound. Also you want to make sure your battery is in good condition. When the starter is full of oil or the brushes worn it draws too much power from the system and keeps the coil from making a strong enough spark.
You may run into problems with the tubing being too flexible from the engine to the fuel pump. I have seen the vacuum from the engine to the pump collapse automotive fuel line. If this happens it can be a real bear to diagnose. Ask me how I know.
The CR500 rod works just fine. ATV racing has used them for their CR500 conversions for years. I would use the lightest of the rods to keep from throwing the rotating mass off too much.
Those parts haven't been available new for probably 15 or 20 years. You are working on a machine that's 30 years old. Your best bet is to keep you eye open on ebay for a decent used steering wheel with the switches already in place.