Welcome aboard!
As for your first problem, it really sounds to me like Throttle Hang.
Here is an article that might be worth reading on the subject.
As for your tranny problems, it sounds like you need to change your fluid. I would not suggest flushing it right now, rather changing only 4 quarts at a time. If you look on the bottom on the transmission, near the rear, you will see a plug that can be removed with just a 3/8's drive rachet. This is the drain plug. After the car is warmed up, place a pan under there and remove the drain plug. Approximately 3.5 - 4 quarts will come out. If you raise the front of the car slightly, with either a jack or using ramps, right at about 4 quarts will come out. After all the fluid has drained out, simple replace the drain plug and pour 3.5 quarts of DexronIII/Mercon approved ATF down into the dipstick tube. Crank the car and if on ramps, back it off. At this point, put the car into each gear while allowing a few seconds for each gear. This will help bleed out any air that might have gotten into the system as well as get everything flowing. After doing this, get out and check the fluid level. If you need to add the other .5 quart, then do so now. If not, then take the car for a spin and see if it has helped anyway.
If you feel that the ATF in the tranny now is the original stuff, then I would suggest you repeat the above procedure in the next few weeks. This will for a better ratio of new-to-old fluid. If you see a difference, then great. If not, then you might have some problems with worn valves in the valve body or worn bands.
Oh yeah! One more thing - After doing the second drain and fill, I would suggest you then get the tranny flushed. That is, if your problems do not get worse. It is a common problem with all automatic transmissions, that the owner does not change the fluid on a regular basis and the fluid will actually eat away at the insides of the transmission. Once a big shot of new fluid in put inside the tranny, the new fluid cleans all this grit and dirt out of little scares all throughout the entire transmission. At this point you will have a hugh loss of internal pressure due to leakage in these areas.
Hope I didn't scare ya, but just wanted to warn ya in case you didn't know. If you have any other questions or not sure of anything, please let me know and feel free to post any of these questions in the transmission forum, which I am a moderator of and visit more than any other forum here. Or you can just PM me.
