I dont understand you?
A 100% black text will result in: C:0, Y:0, M:0 and K: 100.
You cant have pure black text with something beneath.

But du your self a favor, and place the image in InDesign and make the text there, not in PhotoShop.

And no, a proper printing office will not have problems in aligning the 4 plates :)

Perhaps your mac is running out of space on your harddisk? InDesign uses space there while exporting? Creating a small pdf from a very large document requires the same space as creating a large pdf – so secure that there is plenty of free space on your harddisk!

Make a paragraf style and use that to control spacing :)

InDesign only shows a preview og the images. If you add blend mode, InDesign imports the whole image, to make the blend image.
PhotoShop works only with full-res images, unlike InDesign.

So what you see is normal.

If your workplace has an InDesign account, you are allowed to install your copy of InDesign 2 places! Why don’t you just log in to your work-Adobe id, and install InDesign at home?

I don’t think balanced columns work with that – but it is an odd way to make columns – why dont use InDesigns ordinary way, and only use “span columns on headlines?

Or you could export all pages as jpg from InDesign, and then make a “Automate batch” in Photoshop, to make all jpg’s pdf. Final, combine all pdf’s to one single pdf in Acrobat :)