Are your parents directly accountable for your actions after you hit maturity? Because my mother seems to believe her Hereafter depends on my actions and that Allah swt will call her to account for my actions as an adult (which I am).
Short answer is sort of. She's not responsible or accountable for what you do, but she is accountable for not trying to find out what you do and not telling you what is right.
Be a bit more patient with your mother and try to stay put. You said it yourself: "Heaven lies beneath the feet of your mother." It is better than Jihad for God's sake.
So you think that praying in peace while your mother misses your presence is actually better for your Islam and deen? It is not! Just being there and looking kindly at her while listening to whatever it is she is talking about, even if she's just releasing pressure or making senile talk, amounts to making an entire pilgrimage!
God says: "He who is kind to his mother can do whatever he wants, he is forgiven, and he who is unkind to his mother can also do whatever he wants, he will not be forgiven."
If you want to make your Islam stronger, stay by your mother and be kind. If you want endless amounts of deeds, stay by your mother and be kind. If you want your supplications to be answered without delay and your sins to be forgiven without question, stay by your mother and be kind.If you want to be blessed with memorizing Quran faster and learning more about Islam religion and gaining scholarly knowledge, you know what you have to do? Yes, that's right, STAY with your mother and be kind.
When the mother dies, a caller says to the son: "The woman for whom you were being blessed for has died, now you need to do the deeds for which you can be blessed for."
God may grant us our mother's satisfaction with us.