Really lots of tech talk here. I know its important to get good alignment etc.
from where I am imaging on my balcony i dont have Polaris in view and much reference stars to do a really good drift alignment (being at equator 3 degrees north). I have to take exposure subs of the brightest star i can find between 30secs to 60secs long to see where the drift goes and adjust my azimuth/altitude accordingly (this after proper leveling of mount) until i dont see any drift. Ive managed to push 90'' subs with very minimal drift noticed.
Thats the drifting alignment i do now. So far it works enough for me and i get a rather decent image of M13 like below (you will still see the walking noise there)
So with whatever i do and learn now until i get better and better I hope to digest the technicalities as I slowly progress on.
At least i know the root cause of the problem, understanding the solution to it, and then practice it every time I do my imaging.