Those two leaky areas are not difficult to fix. There is a seal which rides on the plastic speedometer gear shaft. Make sure the plastic shaft isn't worn. You can find seal kits on ebay with or without the speedometer gear.
TH350s have a lot of fluid in them, and puddles on the floor always look like more fluid than what is actually there.
The torque converter holds a lot of fluid which migrates into the pan over time, giving you an over-full reading on the dipstick.
You need to drive the truck until the transmission reach full operating temperature, and the fluid gets distributed inside the transmission where it belongs before checking the fluid level while the engine is running.
