Looking for some help with a future booking. New member here and not completely clued up with Priority Club as only joined it when making a previous booking and am only an occasional leisure traveller. Please be gentle with me folks - lol!

Anyway, looking to book a one night stay for three people sharing a room in Edinburgh, Scotland. My preferred hotel is the HIEX Edinburgh City Centre (Picardy Place) as it's really handy for nightlife (having a night out with friends in the city) and I've stayed there before and found it to be of an acceptable standard for my needs. I cannot find availability on any IHG website but can find a room on hotelpronto.com.

My questions are:

Can I earn Priority Club points when booking with a non IHG website?
Is there a way that IHG will match the price when it's not available on their own websites?

I know hotel groups use various channels to fill all their rooms but I find it rather puzzling that I cannot book a room directly with IHG that is obviously available. It is not as if I have gone via another website to save money, I have simply had to do so to find availability! It seems crazy that I am wanting to give IHG money but I can't!

I have looked through the Priority Club Terms & Conditions but found nothing covering this and have similarly failed when searching this forum for advice.

Thanks in advance all.