I'll start with the easier answer, about rule 9: in ALL cases that not only a dock covers an oil rig production, solution is always the same -> adjust the station, relocating station tiles, removing, whatever solution you get to solve rule 9 violation ^^
This problem can appear because a truck station have a coverage of 3 tiles, rail station of 4 and a dock of 5 tiles. But when combined they'll get the biggest one! Other reason can be that oil rigs have tiles that appear not belong to them... but they do! Next 2 images show exemples of both cases:
Main idea behind rule 8 and when combined with rule 7 is: All station parts must be connected, used and not with the single purpose of extending unfairly station coverage. There's several particular situations that makes each case an unique one (antennas, light houses and other unmovable objects). But it's on players side do themselves this rhetorical questions: Why am I building like this? Is there a way of fully respect server rules?
Since we have servers from 5 TL up until 25 TL max station size, the rules need to be the most global as possible. And it's not easy!! Anyway, an honest answer to the previous questions, by the player, will point the legality (or not) of actions taken.
If any specific case evoke doubts on you, feel free to call an admin to analyze them ingame