All good tips!
I did check with my Bernina dealer when I got my 155 and asked why they were so "inaccessable" for cleaning and is it alright for me to remove some screws to clean. They told it it would void my warrantee! I asked how they would know, and they said something about the computer tells them. It can even tell them how many stitches my machine has made!
My old 830 I could take it down to the skeleton practically. I could clean it, oil all the essential parts and put it back together. This was a major change with the upgrade. So be careful about taking a machine apart.
M