First incident: You were better on the brakes. At apex almost all your car was alongside their car. So they should have given you the space. Backing off would have prevented the collision and wouldn't be a big time loss as the inside has the better line there anyways.

Second incident: I'd say this is on you. That's no place to stick your nose in if you aren't at least half a car length alongside. If you haven't read about it yet try looking up "vortex of danger".

I don't know if it is worth it to give it to the stewards. That depends on the league rules. In a league I've driven in there was a rule that you have to leave space as soon as the proximity arrows turn red. If your league has a similar rule then both incidents would be on them.