Janey

I use a nearly 10 years old Macbook pro with 10.13 using a Sandisk card reader. This reader handles CF and any flavour of SD card flawlessly.

I use Photo Mechanic for ingestion, keywording, DAM and export.

Capture NX-D for raw conversion.

AutopanoGiga for stitching.

Photomatix for HDR.

Photoshop as a pixel editor.

Filters from NIK and Topaz.

I would start with a Macbook of some kind, Nikon's free software and a good card reader. ViewNX-i can handle keywording even if a dedicated DAM solution does it easier and Capture NX-D gets more out of the NEF file than most raw converters.

The reason I still rent Photoshop from Adobe is that I know its quirks and most of the shortcuts I need for a fast workflow. For a new user, learning some other pixel editor makes more sense.

iPads can work for editing, but I find touch UI-s harder to use than traditional pointer-driven interfaces. The camera connection kit usually works for transfer from the camera but is a bit finicky with what card readers it works well.