How to remove the comma between Link multi-value field
My suggestion would be to modify the way the links are displaying using the Display Suite module's field templates. Field templates gives you a high level of control over all the ways Drupal outputs the fields.

I found this tutorial that is pretty in depth, but in short you want to add the Display Suite module, enable it and the "Display Suite Extras" module that comes with it.

Next go to the display suite settings and enable "Field Templates." This is under Structure > Display Suite > Extras.

Once those are enabled, find the display settings for your content type (Structure > Content Types > YOUR CONTENT TYPE > Manage Display.

On that page, in the vertical tabs at the bottom you'll see an option to set a layout. Select "One column" or "Reset". Selecting a basic layout here will enable the additional features Display Suite offers.

After your layout is set, you'll see many more options on each field for how it is displayed. You can set the field template to "Expert" and you'll get control of the wrappers, prefix and suffix content (i.e. comma or no comma), and a lot of other stuff.



I hope that points you in the correct direction. Play around with DS a bit and I think you'll really like the control it gives you.