:50 contact is initiated by you, they already had overlap on you. If that was intentional, that would be some hefty penalties as they had every right to be there.
1:20 Technically, they were behind therefore it's on them to make a clean, no contact pass.
1:35 they had overlap so they had a right to their lane. To me though, they appear to drop down and into you. Again, they are they were the behind car, it is on them to make the full pass with no contact. They are at fault.
2:00 That was a bit of a dive bomb on his part, but rubbing is racing and you came out ahead. I probably would assess a penalty here.
3:20. Incidental contact, position was conceded. No penalty
3:40 they make contact, go off the racing surface and hold the position. That would be a dq for that race and a loss of points as well as some stern words from the board.
I judge these from my experience of having been a steward for SNAIL.
A piece of advice, don't be so worried about being defensive that you take yourself so far the racing line. Just enough that you put them further off theirs. Even if they are able to pass you, you won't have gone so far off the line that racers behind have gained ground on you.
This is more geared to the other racer, but, remember this is video game racing with most people on a controller. When you are doubled up around the corner, leave room for the inevitable wobble that's going to occur.
Also, this should be a gentlemen's sport. Smashing down onto someone line that has a clear speed advantage isn't exactly good sportsmanship. Pushing them down to the inside before a corner is one thing. Dropping all the way down to the inside on the other hand. It's slow, it's a good way to get rear ended and it's dirty lobby tactics.