"When will you know enough?". Never. But be cautious regarding what you know. There are no shortage of know-it-all clever-arses out there whose brains are full of useless sh1t. And boy oh boy do they never tire of letting you know how much they know. To which my response is invariably, "Give me any conceivable scenario in which that information could be operationally useful to me in conducting and ensuring a safe flight" The response is almost invariably never, if it's not never then I have learned something useful which is good.
Regarding slavish compliance with SOPs, deviate, if safe to do so, whenever the situation is Non-Standard, assuming that your fellow crew are with you and happy with the non-standard proposal. That's the whole idea of SOPs, they are appropriate when the situation is standard and are inappropriate when the situation is not. The debate doesn't need any further justification. Lastly on this topic, I once worked for a freight airline operating 4 completetly different fleets. Our chief pilot decided that 3 fleets should have their SOPs re-written to match the logic and layout of the senior fleet even though 4 separate manufacturers were involved. Consequently and inevitably the Junior fleets SOPs were rubbish being laced with errors and inappropriate actions.