This might be quite time consuming if you use ObjectDBX and there is a large number of objects in the drawing because you can't (maybe I should say I don't know how to) make a selectionset using filter and you'll have to loop through each object to check its color, linetype, etc.
- Image props-correct layer, insertion point, etc
Image insertion point? Are all the images in PaperSpace? Otherwise, are they all inserted at 0,0?
What are you plan to do after the checking? Do you want the code to automatically fix some problems or you just want it to output the result to a text file?
This should be a challenging and useful project. The problem is if you're talking about checking with that much details, it would be very hard to write the code that's useful to different companies.