Re: capacitive kickback
Capacitors can cause current spikes during charging.
If you have a large amount of capacitance on the input of your PCB then several amps of current can flow for a few milliseconds when you first switch on the device until the capaitors are charged. This can cause problems with over current protection on your power supply. One of the most common problems with this is on USB powered devices where the device must maintain less than 500mA current drain, hence why you get a warning sometimes when you plug USB devices into your PC/laptop.
When power is switched off you won't get a high current discharge analogous to an inductor kick, due to the RC time constant of a capacitor discharge, you are more likely to see the capacitor take a very long time to discharge as it doesn't have a path to easily discharge to ground. Hope this helps.