For charging lithium ion (LI-ion) batteries abroad the best and safest thing to do is to purchase the battery charger from the camera maker suited for that country’s electrical infrastructure and specific to your camera. Second option would be to buy a aftermarket charger that is meant for the battery you have and can accommodate foreign voltages and frequencies. I wouldn’t recommend running your US charger through a universal converter unless you have purchased a really good one meant to have more than a shaver or hair dryer plugged into it.
Lithium ion (LI-ion) batteries are especially touchy and can easily (as you indicated) self destruct if not charged properly.
If you go with aftermarket look for a “smart charger” with Auto-Shut Off and Multi-voltage Charging. Multi-Voltage function in this charger automatically selects the correct voltage for charging in foreign countries allowing it to charge lithium ion (Li-ion) batteries worldwide. An adapter plug may be required for charging in countries other than the USA unless included with charger.
We have a couple after market ones on BetBuy.com, you will need to see if it will work with your camera and in the countries you will be in.
DigiPower - Lithium-Ion World Travel Charger Model: TC-370 | SKU: 6218611
DigiPower - Travel Charger for Select Digital Camera Models Model: TC-500PFC | SKU: 8471815
Sima - International Travel Plug Set Model: SIP-3 SKU: 7012332

This will have to be a 2 part answer. I'm checking into the audio edit function. As for playing the hard drive contents to TV for preview, that can be done with the AV cable supplied with the camcorder. If you have a stand alone dvd recorder you can record up 8 hours (on some models) directly from you camcorder. The camcorder itself will burn 60min on a dvd per side in STD mode. Using the computer you should get up to 2 hr, I'll try to confirm that also.

If it is a Digital Camcorder you need the software to “Capture” the footage once you connected the camera to the Firewire port on your computer and the iLink port on the camcorder. If you do not have a Firewire port it needs to be added, or you can get a A/V (Audio Video) Capture box such as Dazzle Digital Video Creator Platinum from Pinnacle and connect your camcorder to it. If you do have a Firewire Port then you can install editing software such as Adobe Premiere Elements 4 to capture and edit the footage. If it is NOT a Digital camcorder and just a Video Tape type camcorder than the Pinnacle system would be best. Both systems are very easy to use and will give you great results.

There is no cassette converter. Hi8 is a special 8mm tape that runs at a special speed . VHS is 1/2 inch tape that runs at a different speed altogether. Plus the video heads on doth machines are not compatible. If you have the camera the video was shot on you can run the A/V (audio video) out to the VCR and make a copy. If you do not have access to the camera a Digital 8 camera will play back Hi8 tapes.