OR you could do like others, like @cowpuc has done for his last 200K miles, just do not use second gear.
The lose of 2nd gear is not something that will cause any additional damage to anything, so it is safe to ignore it. You can at least put it off for a winter project while you watch the SNOW fall.
You can often find complete newer transmissions that have the "fix" on ebay to just drop in.
Second gear is a issue on most all 83, 84 and early 85 Ventures. It was mid 85 that Yamaha fixed the problem.
As for the CLASS (Air Ride), it to has a common issue with bad solder joints on the connector to the circuit board. Also the CLASS will only work with the key in ACC, it will not work in RUN, this is by design.