Yes, Corpus Railjack nodes should all become Skirmish, like the Grineer nodes. There's a good variety of main objectives on skirmish already, I don't see why someone would go to Railjack wanting to play Survival or Defense.

I do the same configuration on my crew, I just focus on piloting and let them do the shooting. Been ages since I was boarded.... only complaint I have is having to leave the pilot seat to shoot the Artillery.