I'm inserting large inline images into my text flow, which it then breaks the flow and disappears. Is there a way to have it automatically resize to fit the text frame's boundaries?
Make and adjust your graphic frame, then copy your image and 'Paste in to' instead of regular paste. Is this what you needed?
There is no way for InDesign to contextually scale inline images. However, if the images are single color vector images, you can import them as glyphs into a custom font using something like IndyFont. It turns InDesign into a font editor, allowing you to paste in vectors, and save it as a font (even a single-character font). InDesign treats the font glyphs like any other letters, accepting color swatches and scaling with the rest of the text.