Raymo, I too am bowled over by the quality of your work. I seem to have the same equipment - 8"f5 on HEQ5 and Canon 1100 - so am eager to emulate.
Do you use a Bahtinov mask for focus?
Are there any special settings and modes of the Canon you use?
Have you experienced any problems with vibration from the camera mirror flip up? Earlier Canons had a mirror-lock function not on the 1100.
Kevin