Why does my cupcake texture end up with a watery-scrambled egg texture, with a sulfurish smell
I wonder if perhaps you've made a typo in regards to the proportions of this formulation. Try to source a reliable and tested recipe and compare ingredient components to modify what you're trying to achieve.

Please note, baking soda and sodium bicarbonate are identical ingredients.
Also, it is good advice to not open the oven until the cake(s) are close to completion.

I'd love to inquire as to the reason you are adding titanium dioxide to butter/trying to "whiten" it. 

As for the off-aroma, ensure the eggs you use are fresh.

I hope this is more PC of an answer.