About the bank statements, I use a bank account just for immigration. It has a monthly foreign deposit and a single monthly withdrawal. My immigration printout might be 2 pages. Immigration doesn’t need to see all my purchases or other deposits for the year.
My immigration demands documentation for a foreign source of income, not just transfers. I use a pension verification letter. Does the immigration you use have that requirement?
Do an international transfer every calendar month for 12 months, and be able to show a source of foreign income. If minimum qualifications are met, it is easy. If minimum qualifications can be questioned then it becomes difficult.