AC Adapters and Chargers

No this is not normal. When the AC adapter is plugged into a laptop and power supply the light remains constant. If the light flickers, the plug may not be inserted properly into the power supply, the power lead may be faulty or the AC adapter may be faulty.
If the battery will charge in the notebook computer but will not charge in the external charger, then the battery and the charger are not compatible. If the battery does not charge in the external charger, or in the notebook, then it may be defective.
Overcharging creates excessive heat which can cause the battery plates within the cells to buckle and shed their active material. Permanent capacity loss will result.
Yes, as long as the boat has a DC output similar to a car (cigarette lighter socket).
Yes, the AC adapter will get hot whilst it is plugged in and being used. This is normal. Any device that gets hot will require ventilation. Good ventilation prolongs the life of the device and avoids any accidental damage.
Yes, universal chargers are now available which come supplied with different tips. By using these tips different laptops can be connected to the one charger.
Yes, universal car/air chargers are available. It can be either used in a car's cigarette lighter socket or in a airplane power socket found near the seat.
Make sure that the AC Adapter is plugged in properly and that all the other leads are also plugged in properly. If the light comes on but it still doesn't charge, then the cable connected to the laptop may be faulty or the socket on the laptop may be faulty. If the light doesn't come on then the power lead may be faulty, or the fuse in the plug may be faulty or the power socket on the wall may not be working. Intel has an interesting page on issues with AC Adapters and their processors.
Make sure the battery is inserted properly into the laptop and the AC adapter/charger is connected and plugged in properly. Make sure the battery is the correct battery for your laptop computer. Make sure the wall socket where the AC adapter/Charger is plugged into is working properly.
Insert the battery inot the battery compartment in your laptop computer, plug in the AC adapter/Charger and keep it plugged in for about 4 - 8 hours.
As long as trucks have a cigarette lighter socket with 24V DC output then the car charger will work in the truck.
Check your notebook computer's manual. You can calculate the wattage of your notebook computer by multiplying Volts(V) with Amps(A). This information is found on the label on the underside of the notebook computer. By carrying out this calculation the wattage of the adapter can be matched. Where the notebooks's wattage is less than 70W, either a 70W or 90W AC adapter can be used. Where the notebook's wattage is more than 70W but less than 90W a 90W AC adapter should be used.

Yes, but you will need to check a few details. Firstly, the voltage. AC supply in the country you are going to use it should be within the range of 110 - 240V. Secondly, the plug type (which is inserted into the wall socket). As long as the voltage is within range, plug adapters can be used to fit the different types of wall sockets.