Can I use standard computer vision techniques for images taken in the NIR spectral range?
As far as I know, it is a common practice to use regular image processing techniques in this field. In fact I have recently finished a project in this field.


  if it is possible to employ standard stereo matching algorithms like
  block-matching to images taken in the NIR spectrum and if so would it
  be possible (of course depending on the conditions) to obtain a dense
  depth map.


Yes, it is, I think, since NIR images as opposed to Far-Infra red Images has a lot of texture which you probability can (It is very very similar to RED band of the image), as an example people doing these:

repository.upenn.edu/cgi/viewcontent.cgi?article=1115&amp;context=cis_reports 


  if standard feature detection and description techniques like SIFT, HOG,etc produces similar results in the NIR spectrum.


I think so, since again it has lots of texture and wherever there is texture is corners, edges and all types of  feature points,which you can extract for further porcessing, check this out:

enter link description here

I think you are better to also take a look at reference books such as:

Machine Vision and Advanced Image Processing in Remote Sensing:

https://books.google.com/books?isbn=3642601057

Remote Sensing, Models, and Methods for Image Processing:

https://books.google.com/books?isbn=0126289816

Hope you've got your answer.