Yes, this is an astroscience fact. Because it is the sun and it emits all types of stuff.
But planets are a different thing. They only emit infrared (warmth) and reflect what they receive from the sun and other energy sources.
Yes it is. However it is a self-sustainable gravitational field.
Everything that has mass has also the gravitational field.
There is no energy required to sustain the gravitational field.
But for an object to emit electromagnetic waves, this object must somehow sacrifice energy (or reflect energy that it received from somewhere else).
About astrology:
In some other esoteric non-scientific text that I’ve read one shall not take it literally as “a physical influence of the planets”, but rather that everything in the universe follows certain patterns and certain probabilities on earth correlate with certain locations of planets in space-time, and vice versa.
It is an invisible correlation of patterns, probabilities and potentials.
But not a direct physical influence of planets (except for the sun and the moon, those have many physical effects on life on earth).
PS:
Let’s see what the astrology experts will say, I am curious to know myself about their understanding.