This is bullshit. Photoshop for design? That's just wrong on many levels. Photoshop is for raster image editing, not for layout, copy or design. I mean, you could use it, but that's like cooking with a washing machine.

This is obviously a job for a vector based software, the file size shouldn't even exceed 1MB and even a 15 year old computer could handle the software (Inkscape, Affinity Designer, Adobe Illustrator, Adobe InDesign, hell, why not CorelDraw or Quark XPress or Macromedia Freehand; this last 2 is 20 year old software, but still very appropriate for the job, certainly more than Ps).

About the bleeds: talk to your printer, there is no universal formula from that and differs from shop to shop.

Never raster, save as PDF and talk to your printing person. Don't bother with dpi, it's not relevant if you do it right (vector).