Try to not get overwhelmed, its easier said than done, but i'll try to help.
First, sectionalize, pick out the easiest/cheapest things first.
Headlights, they shut off randomly, however operating the switch fixes it. Could be two things, the headlamp relay, or the switch. Given that you also have interior light issues, my bet is on that switch. replace it with one out of a junkyard or buy a new one. Replacement is easy, just 3 bolts and the connectors on the back.
Hopefully that fixes your lighting issues, now, onto the spedo.
Do you have any codes for it?
First thing to check is the operation of the cluster itself, barring any pertinent codes. First, put the key in and in the off position. Then depress the odometer button, while holding the odometer button turn the key to run but do not start. After 2-3 seconds release the button and watch as the LCD segments go through their check as well as all the LEDs. During this time all the gauges will move together throughout their range. They will stop at about 1/4, 1/2 and full sweep, each time taking a second to pause.
If any error codes show on the LCD, make sure to note them. If any of the gauges or LCD segments fail the test, the IC must be replaced.
Should the IC test good, you then have to check for connection to the ABS module, since we cannot connect to the bus without expensive equipment, you are just going to have to goto the ABS module and inspect it. Unplugging it should throw an ABS light as well as a check engine light. There are other posts around here for more in depth diagnosis for this type of problem.
That leaves us with stalling and transmission issues. Stalling could be caused by a MAP sensor, if you have the new one, might as well put it in, to test. This problem could also be caused by an IAC that is going bad, or by the transmission itself. Checking for codes is really a must to fix these two problems. However a fluid and filter change on the transmission with a band adjustment wont hurt, and may fix the problem if its simple like a clogged filter.
As for the stalling, if there are no codes, check the spark plugs for excess fouling, that could indicate a few things. Checking the air filter as well is an easy thing to check off the list.
Good luck.