1. Depends on what is your understanding of parking mode. There are basically 2 type of parking mode.

First type is the dash will turn off when you park. However it will wake up and do recording when the g-sensor detected movement or shocks. This type of parking mode does not need hardwiring as there are battery in the dash that have enough juice for it to work for a couple of minutes.

The second type is continuous recording. When car is parked, the recording will be low framerate and/or low bitrate. Once car starts moving, it will record back at normal rate. This type need continuous power means need hardwiring.

2. Not sure about this but you can use a piggyback fuse tap which does not modify any of the electrical components. Picture below:

1. Yes as most dashcams using capacitor needs to be hardwired. But those with battery inside can record video AFTER getting the g sensor triggered without hardwire.
Nowadays have hardwire to fusebox or via the OBD port.

2. I know all car manufacturers will void the warranty for anything not installed from the factory. There was a case for a Civic owner changed speakers and using LED bulbs and somehow a fuse blew. Sent back to SC to check and SC reported to Honda Malaysia modified. 5-year unlimited mileage warranty byebye for whole Civic. So depends on the SC.

If your car has an issue with electronic, go to accessories shop first to remove the hardwiring before go to check or claim at the service center. but during installation, you need to make sure plug and play and not cut any wire.
I do this all the while and never void any warranty. This also has to depend on the Service Center that you go. 

Depends on the car makers as for my CX-5, everytime I send my car to Bermaz Glenmarie for servicing (already done up to 40k servicing there), the SC will take photo of any modifications done that are visible.
Some of the CX-5 owners who don’t want to hardwire their dashcam but need the parking mode will spend extra on external battery pack, which easily cost Rm1k or more for Thinkware or Blackvue battery pack

No, if strict enough, you have to remove it for every single visit to the SC. So better you learn how to remove and reconnect yourself. Cuz your car might break down suddenly, electrical fault and requires towing to the SC. Going to tow first to the shop to remove then only SC? Hassle..   Like being said, some centers will take note of every single mod done on the car. Whether "plug n play" or not. All grounds to deny warranty claim should they desire.

Normally they not going to F*ck u for normal service. they just do their normal service and mostly is not interior. also if you want a claim, for example, your absorber or anything not replated with electronics, no need to remove. Only need to remove it when you want to claim a certain part due to electronic failure.

My car had install auto fold mirror, auto door speed lock, they not even f*ck me. I did claim my side mirror fold issue, and before I go to SC for a claim report, I went to accessories shop remove the auto fold wiring and I do not have an issue with the claim at all.



Every time when you go service your car, try to be good with the Manager there might help a lot too.