I wrote my thesis in Word (graduated last friday, vivad last march). The key to stop things moving around in word is to use the "in line with text" option for images. And treat images like text. If you want it centred then justify it to the centre, dont try to place things manually.

Previous documents ive written with word i would do things like tight layouts on images, maybe with anchors, but that's a recipe for things moving around.

When i came to compile my chapters to a final document i used master document-subdocument to pull everything together. I only had a few issues with blank pages being added when exporting to pdf and that was due to my use of page breaks and section breaks.