1995 Toyota 4Runner 4Runner runs rough while idling in gear

My 4Runner runs very rough occasionally while the vehicle is in gear and idling (i.E. At a stop light). Also, while accelerating, it seems to miss badly at around 2700 rpm. If I accelerate from there, it starts running stronger, but if I hold it close to that rpm, it will continue to miss. Further, (and I realize that this is a different problem) the transmission overheats and spits tranny fluid out all over the back of the vehicle whenever I pull my very small fishing boat for over an hour at highway speeds. (55-65 mph) When this happens is it better to turn the overdrive off and slow down a bit? Thanks in advance for any suggestions.