'93 Plymouth Sundance that needs a little loving

[/i]I just bought a '93 Plymouth Sundance that has a few things that need attention. If anyone has any advice I would greatly appreciate it!
So here are the problems:
The greatest is that the transmission is having some difficulties shifting, especially in the cold. When I first start the car I really have to rev it so it will shift into drive. Then sometimes it will stay stuck in second gear, going up to and above 3000 rpm when I am just trying to go the speed limit at 35 mph! I figured out that if I just stop, shift into neutral, then restart the car it fixes it but it still worries me greatly.
Along the same lines, the heater is having a difficult time. I think it has something to do with how my engine seems to have a hard time getting warmed up, sometimes taking up to twenty or thirty minutes before I drive. Then it cools right back down when I start to drive. And it never is able to maintain its heat when I am going at higher speeds.
One other problem is that three out of the four doors does not open from the outside. They open from the inside but it is quite annoying because one of the doors that does not work is the driver's door and having to crawl over the passenger seat to open it gets old. The handles just don't seem to do anything from the outside.
Also, the horn does not work. I hope this is not because something has been tampered with something in the shaft of the steering wheel. Is there any fix?
A minor problem is that the right turn signal does not work. It just comes on but does not flash. I have to operate it manually.
Last and what seems to be the most minor problem is that the windshield wiper fluid shoots straight up in the air instead of on the windshield.
So if anyone has any advice, even if really minor, I would really appreciate it.
Thank you!