This is not new technology. Charging batteries at a higher rate when they are discharged and reducing it as they get closer to capacity is common and has been done for many years.
If done correctly (and I'm making that assumption), it should have minimal effect on battery life. Batteries only heat up when they are charged at a high rate as they get full. That is why the charge rate is reduced as they get closer to capacity.
If used occasionally, it is unlikely to have much impact on battery life.
If the battery is truly charged, the rate at which it is charged doesn't affect how much energy is stored. In other words, this is probably just an illusion.
This is possible, but unlikely unless the cable is bad, or has a bad connection,. Any decent cable should work fine.
If plugged into a 110V outlet (or 220V in Europe/UK), the charge will not be affected by where it is plugged into.