Transmission Issues

I have a 95 Pathfinder with an electronic auto transmission (RE4R01A) that is shifting a bit hard and likes to stick in 2nd and 3rd unless I let up off the gas a bit. Also, when I put it into drive, it takes a good 3-5 seconds to fully shift into gear. Lastly, after I drive it for 10mins+ the transmission fluid on the dipstick is up to the "hot" range and will leak about an ounce or two until it cools down which is when it will stop leaking. I cannot tell exactly where the leak is coming from, but it eventually ends up dripping off the large metal band (no idea what it is called) just behind the oil pan in between the engine and the transmission. A few drops will also end up on the bottom of the oil pan, but the majority falls from that metal band.
After reading a ton of info from different forums and Q&A websites about electronic auto transmissions it seems that my course of action to try to fix this problem should be to:

Flush transmission fluid cooler along with the fluid itself and replace filter
Add an additional transmission fluid cooler if the problem isn't fixed
Find faulty sensor causing hard shifting / sticking in third
If all this fails, swap auto transmission for a manual

A couple questions about this is, how reliable are transmission cooler flushes? They are only $10-$20 which makes me wonder if they are effective and if they will harm my transmission even more. Also, if I flush the transmission fluid and replace the filter, won't this clear the junk out of the fluid cooler? If I add an additional tranny fluid cooler, and the stock one is ineffective, will this be beneficial or since the fluid isn't circulating efficiently will it not do any good? Finally, when I hook the Pathfinder up to a computer it doesn't register any faulty sensors, so does that mean that all the sensor are functioning, or could a sensor just be half-malfunctioning and the computer doesn't pick it up?
Sorry for all the questions, but I am new to transmission issues (if you hadn't guessed) and any input would be greatly appreciated.

My 1995 Nissan pathfinder was shifting real bad too. Just like you described. It wasn't leaking really, but it had a real hard jolt when it moved from gear to gear. So I flushed it. BIG MISTAKE. The flush actually improved the shifting for about a week or two, but then shortly after, reverse went out. The transmission guys that rebuilt my transmission told me that the other gears were about to go out as well. I got the whole transmission rebuilt for $1300 dollars.

So I would not flush it. Especially if it has over 100,000 miles on it.