DrNeh, you are clearly keen on teaching your child and have asked for advice on nurturing his intellect. I too was keen on teaching my dd, as I believe education, as well as genetic intelligence make up ability.
There clearly is a strong father-son bond, but teaching a child involves listening to them. Just try writing one letter and ask him if he knows what sound it makes, in a way that lets him know you are genuinely interested in what his answer will be. Give him time to answer and ask him if he is still thinking or should you tell him.
Use lower case letters and letter sounds rather than names. Try writing and sounding out simple CVC words, where each letter makes a sound; ie, d o g rather than c ar. Then draw that thing or hand him a toy dog so that he can make a connection of letters making words and meaning things in a fun way.
For maths, play games: You have two sweets, if I give you one more how many will you have? Cut out different shapes, put them at the far side of the room and get him to run over and get the triangle. Play shops. Bring teaching into play and play into teaching.
As for nursery, his social skills are every bit as important as his academic skills. There are a lot of hours in the day and very few of them, (made up of a few minutes every now and then), are enough to teach him academic things. Children needs a good balance of meeting other children, playing in the park and even being left alone to just daydream.
should we not try to nurture the natural talent he has ie strong intellect, memory and brain power. Giving him a love of learning, the realisation that working at things will improve his ability and the humility to realise that he was one of the people lucky enough to get a good education, is a far better plan.