My questions are mainly for those who have used Mini 2 for a long time, but I would appreciate any answers to either one of the questions.
1. Does the drone need part replacement after some time of usage?
2. Does any part degrade over time requiring replacement after a few uses?
3. I plan on buying just the standard version, but the fly combo pack comes with multiple sets of new rotors. Does this mean that rotors have to be replaced regularly? If not, why are there spare rotors?
4. How does the battery fare over time, does the capacity degrade significantly requiring replacement at any point?
5. How often does the drone fail on its own, not due to human error?
6. I have seen a few videos where for some people one of the rotors during flight comes loose and the drone crashes. Does that simply happen eventually due to some internal degradation of the motors or rotors, or that is also just human error where a person most likely didn't attach something properly?
7. Can you fly the drone in misty conditions?
8. Does Mini 2 have strobe lights underneath it? This seems like a simple question for which answer should be easy to find, but surprisingly no reviews mention this and I can't find any photos.
9. This might be hard to answer, so feel free to completely ignore this one. If I don't get the DJI care (not available in my country it appears), and happen to crash the drone heavily. Is repair in such cases feasible or is the drone usually damaged beyond repair and it is cheaper to get a new drone?
10. What happens if the drone doesn't find any or just couple of sattelite connections, does it pervent the drone from taking off?

1. Does the drone need part replacement after some time of usage?  Not usually
2. Does any part degrade over time requiring replacement after a few uses?  NO
3. I plan on buying just the standard version, but the fly combo pack comes with multiple sets of new rotors. Does this mean that rotors have to be replaced regularly? If not, why are there spare rotors?  They are included in case they are damaged by running into something. You should replace blades in pairs.
4. How does the battery fare over time, does the capacity degrade significantly requiring replacement at any point?  Yes, batteries do not last forever. But I have yet to need a replacement after almost 2 years.
5. How often does the drone fail on its own, not due to human error?  Very rarely, I have had no drone failures in flight for my 6 drones. One failed but the cause was probably operator-inflicted.
6. I have seen a few videos where for some people one of the rotors during flight comes loose and the drone crashes. Does that simply happen eventually due to some internal degradation of the motors or rotors, or that is also just human error where a person most likely didn't attach something properly? Most likely cause is improper installation. I have never had one come off or even loose.
7. Can you fly the drone in misty conditions? I think so, but I would avoid salty mist.
8. Does Mini 2 have strobe lights underneath it? This seems like a simple question for which answer should be easy to find, but surprisingly no reviews mention this and I can't find any photos. I do not remember, but I don't think so. If you want a strobe light, I recommend putting one on top at the front.
9. This might be hard to answer, so feel free to completely ignore this one. If I don't get the DJI care (not available in my country it appears), and happen to crash the drone heavily. Is repair in such cases feasible or is the drone usually damaged beyond repair and it is cheaper to get a new drone? Sometimes the repair can be done by an owner who is familiar with such repairs. I have repaired my Mini 2 (new motors on two arms) and a Mini remote control (bad connector). Most parts are available online from third parties and there are many online videos describing the processes.  Arm/motors were $30 US each; connector board was $10 US.
10. What happens if the drone doesn't find any or just couple of sattelite connections, does it pervent the drone from taking off? No, but it will be in ATTI mode which requires a lot of attention of the operator. It will not stay in place well while hovering over 30 feet high. Darkness can also hamper the perfomance. Losing both GPS and lighting of the ground below is the worst case situation and the drone may be unstable.

As Gary already answered correctly, just a few remarks to add.

- try to avoid rain and mist situations. A small amount of licht fog won't do much harm. But electronics don't cope good with water. The small water particles mist is, can go into the ventilation openings of the drone and cause  problems.

- Flying DJI drones for some years no, without any error. Just be responsible and understand your drone. Don't neglect any warning messages you get on the screen. When you got your drone in the air, watch it's behaviour. When it drifts without touching the controls, get it down and calibrated the IMU.

- Check wind before you fly. Wind can be harder when flying higher. If you get headwind returning home, fly lower. And don't wear out your batteries so much, you can't make it home.

- Most severe malfunctions are human error. Try finding some YouTube video's on safety. Doesn't matter the drone, rules are the same.

10. What happens if the drone doesn't find any or just couple of sattelite connections, does it pervent the drone from taking off?

If you try to launch the drone out in the open, where it has a clear view of most of the sky, it will always find more satellites than it needs quite quickly.
But you should wait for it to get good GPS data and record a homepoint before launching.

there are led lights on the drone so you can see it at night but there are no strobe lights for long distance warning purposes.

Thank you all for the answers, they all are very helpful!

GaryDoug Posted at 10-13 12:28
1. Does the drone need part replacement after some time of usage?  Not usually
2. Does any part degrade over time requiring replacement after a few uses?  NO
3. I plan on buying just the standard version, but the fly combo pack comes with multiple sets of new rotors. Does this mean that rotors have to be replaced regularly? If not, why are there spare rotors?  They are included in case they are damaged by running into something. You should replace blades in pairs.

Great assist Gary.