Sect. 1. I suggest to modify the text as follows: The source of the surface magnetism in the Sun lies in a deep-seated dynamo situated at the bottom of the convection zone, the layer of the solar interior just below the photosphere. The magnetic fields underlying solar and stellar activity arise from some combination of convective flows and stellar rotation.
I don't understand what you want to say with "emissions" in the following sentence. Please check. With modern observations this provides vector information (via use of the full Stokes parameters) of the emissions, ...
After discussing coronal magnetic field measurements, you abruptly return to the photospheric ones (network boundaries). Please make this clear, e.g.: These measurements -> Photospheric magnetic measurements
Last sentence: I don't understand what you mean by: "...diverting a part of the solar luminosity away from the photosphere." Please check.
Figure 2, caption:
Please add that blue and red colours show magnetic flux tubes of opposite magnetic polarities.
fast risetime -> fast risetime of brightness
Sect. 3.3, end of 1st para:
"emerging flux regions" is a label generally used for major flux emergence, so it doesn't seem to fit in the list of small-scale events...
Sect. 4.1: there are too many "for example"s before Figure & is referred to.