Watching those incidents, it's not entirely the fault of the other driver.
This comes down to your speed and experience on circuit and with others around you. I have found when drivers are not in the higher driver rating class, then lap times, although similar, are gained by different speed in different places around the track. This can make it unpredictable as to where an opponent will brake and what line they will take.
For example, your first video. You are taking a very slow line through the final chicane at Yamagiwa. From the other car's perspective, that driver appears to be taking a more normal line, and braking where they would expect you to brake. You are braking earlier and running slower, so he takes avoiding action/turns it into a pass as you can see with the change in direction. The bump appears accidental. It didn't appear to be a dive at any point.
2nd video appears unlucky. The driver was very foolish to rejoin like that but the game shouldn't have de-ghosted them there. Try to learn from it, but even the best would get caught out there.
3rd video, once again a slow line through the corner. The 2nd driver takes a faster and more normal line while you are running very slowly on the inside of the circuit. The 2nd driver doesn't appear to care that you are there and bumps into you, but also didn't appear malicious in the bump.
4th video, you should have given up the position. You were side by side into a corner only 1 car can go through. The other driver doesn't necessarily respect you are beside them and give you racing room. But watching that video you are on the brakes way to late and was probably heading off the track anyway. In that position, they had the high ground, and in future you should recognise that and give them the position before it turns into an incident.
One thing I have learnt is, especially in DR B and lower, to give the opponent more room than they need. Recognise when you have the low ground and will turn into an incident if you fight hard and learn from the accidents. Don't get angry in the race, it may annoy you for sure. But at least watch the replay, watch what the opponent did and how they reacted to you and what you were doing. Learn from it and try to more actively avoid accidents in the future. Sometimes it's better to let someone by than to fight it and be bumped off costing you many places. So many times I have been annoyed by the behaviour of some drivers where I was just as much at fault as they were. It's always easier to blame someone else rather than yourself.
3 of those scenarios, both drivers could have driven better. I'm not blaming you at all, just trying to open up the idea that it takes 2 drivers to have accidents like those. Hope you can take those thoughts on board and have better races in the future.