Purchased My Odyssey, NEED HELP

I have always wanted a Honda Odyssey 350 and 23 yrs later i finally got one!
It is a 85 in very good shape but has been sitting for some time.
Ok, it was said to be sitting for 2-3 yrs without moving. Im new to this "old" technology and any and all info people can give me or direct me to would be GREAT as its a bit difficult to find info on these older machines.

***The electric start doesnt work (have read about the starter/oil issues..no big deal to me)
When i pull start it, it starts right away. After it idles for a couple minutes, it makes alot of noise coming from the belt area i think. If i barely touch the trottle ( i mean barely) as the rpm's come up a lil, the noise goes away. As soon as it idles all the way down, it makes the rattling/noisy sound. Any idea?

***The next thing is the shifter. It grinds when i put it in Fwd or Rvs. It does this if i have just started it, or if i drive it, come to a stop and let it idle for 15 seconds. If i come to a stop and imidiately shift it, it does not grind at all. I dont like the fact i have to kinda force it into gear when its just started and cold.

***The next is im sure it needs a tune up! or carb adjustment. When i accellerate, it doesnt like it unless i bring it up slow/half throttle. I took it out on the street to see what she would do the other day. I slowly accelerated and the next thing i knew i was screamin along im guessing about 50mph then it fell flat on its face, sputtered, pop'd and lil flames coming out of exhaust.
I replaced the fuel lines, i replaced the fuel filter and the spark plug. Also ran new gas 87* with 32-1 ratio 2 stroke oil. I also pulled the carb and carb cleaned it.
Still it runs ruff unless im just putting around.
I love this machine but need help / tips getting her up to speed!
Thanks for any info or places to find info.