No! These are lithium batteries and your device charges NiCd and NiMH batteries. The NiCd and NiMH also have 1.2V voltage, these Pale Blue have 1.5V. The charger may have a problem recognising when the battery is charged. There are Li chargers, but I wouldn't risk it with the batteries.
No, because the batteries need a constant charging voltage of 1.6-1.7V, which not even the quite intelligent chargers or the automated ChargeManager from Conrad (which only charge NiMH or NiZn) provide. In addition, the chargers most likely do not recognise when the battery is charged, as the charging electronics are located behind the USB port and not at the poles of the battery. Therefore, use the cable supplied, which allows you to charge up to 4 of these batteries at the same time (provided the charger can deliver 2A to the USB port).
Yes, it should work. However, a charging cable is already included in the scope of delivery.
The green strip lights up as soon as the batteries are fully charged.