Is it necessary to follow one method when seeking to know the Shariah ruling, or is it permissible to differentiate between major and minor jurisprudential matters? And is it wrong to ask more than one source to reach the most appropriate opinion?

We do not fully understand your intent regarding some of the terms used, but we will clarify several matters for you: 1. Not everyone is qualified to examine the religious evidence; rather, it is for specialists. 2. Adopting the opinion of the majority is only correct if it does not contradict the preponderant (rajih) view. 3. A layperson should seek fatwas from someone whose knowledge and religiosity they trust. 4. There is no harm in asking more than one scholar for verification and learning. 5. When fatwas differ, the most preponderant (arjaha) is to adopt the easier opinion, as long as it does not lead to corruption. 6. It is not permissible to follow the blameworthy practice of cherry-picking concessions (rukhas) from different schools of thought, but taking a concession out of necessity is not part of this. Based on this, there is no harm for you in sufficing with asking someone whose knowledge you trust, or asking more than one person while verifying the evidence.