You have too many questions.
1 If you understand private electricity supply companies as the "individuals" you mentioned, there should already be individuals investing in wind energy storage and generation projects and solar in China, and there should be no purely personal investments. solar energy production projects (the rate of return on investment is not good).
2 Solar panels are just photoelectric conversion devices. The energy production of solar panels is static and there is no "intermittent" problem as you imagine (is your sleep harming your health because you are not working continuously)? Once connected to the Internet, the power grid is like a large dynamic mechanism that can completely compensate for "intermittent" solar energy production (just like many people go swimming in the river but thewater surface does not change).
3 Ordinary small solar panels generally do not use light chasing service mechanisms, because this is not as cost-effective as increasing the surface area of photovoltaic panels. Some large-scale solar power plants will use light tracking service mechanisms.
4 The power of the solar power generation panel is mainly proportional to the area of the photovoltaic panel, and on the other hand, it is also related to the technology of the photovoltaic cell.