Nothing like beating a dead horse. PDF's for print

I know it's been a subject that flares up often but after starting my day today I feel I must bring it up once again.

We often receive requests from our local college to produce foamcore "posters" to advertise their upcoming events. The files are designed by the "graphic design" students. They're given to us via a download link. No problem. Drop the zip folder to my pc and unzip. The files are 8 posters and right away I can tell they're from MAC. Not that I care but...we don't use the over bloated, overhyped mercedes computers. There are 8 pdf's. Work request say's "they're all to size" already but calls for a finished size of 24'' w x 35" h. Actual size =  24.7516w x 35.7536h.

First thing I try to do is import them into cd as I'd like to keep any vectors as vectors. Nope! Fonts weren't converted (school mistake #1). Fine! Import as curves. Fonts are vectors but the image behind is "chunked" i.e. comprised of several rectangles. I'm not entirely sure the reason. Maybe a pdf fault that can't handle making a file that size? Anyway, let's move on. Many will tell you to "not worry about it", it should still print fine. I will tell you from experience that it will not print fine! I know a workaround that I'll get to in a moment. At the same time that I see this "chunked" problem I notice to that the pdf files have "Prepress Marks" (school mistake #2). I have told the instructor several times that we prefer not to use them. Something else I could explain, and have in other posts.

On to the "workaround". I don't mind workaround's but it does add to the "art time". I'm the only designer in a very busy sign shop with a crew of 7 or 8 employees not counting the owner. Our shop sits about 3 miles from the largest USAF base in the world, about 10 miles from another AF base, 3 miles from a major college, blah blah blah. It's dang busy! "So I open each of them in photoshop. Oh and btw they're 300 dpi (school mistake #3). I created an action in photoshop to flatten,  save as tiff, then close that file, do the next etc. Once I run the action on each I then import them to cd and powerclip them into rectangles and press on.

In conclusion I'd just like to get opinions as to what the instructor could do differently. I know, for one, would I'd like them to teach to always convert text on pdf output. You're just asking for trouble if you think embedding works. I'd also like them to teach that not every print shop uses prepress marks.

Thoughts?