Are solitude, a love of listening to the Quran and lectures and being moved by them, and an attempt to alert others to Sharia-related errors, along with a desire to embrace the Quran when reading it, considered evidence of drawing closer to God and adhering to the religion, or does it represent extremism and takfir?

Your love for good, your being touched by the Quran, your crying out of fear of Allah, and your dislike of abominations are all proofs of the sincerity and acceptance of your repentance, and that you are on the right path. However, do not be overly strict with yourself or others. Advise with gentleness and leniency, without raising your voice or supplicating, as this is the divine methodology in da'wah (inviting to Islam), as Allah Almighty said: "Invite to the way of your Lord with wisdom and good instruction," and Allah commanded Musa and Harun to be gentle with Pharaoh: "And speak to him with gentle speech that perhaps he may be reminded or fear [Allah]."