Wedding etiquette?

Yes.

Yes and no.

To me a 'couple' should be invited to the same parts however sometimes it is a little prohibitive due to space etc and she needs her friends to be a little extra understanding and just go along with whats needed. HOWEVER throwing your toys a little and saying no point in going is a little childish IMO.

In all honesty I think it depends on how close you and the bride and groom are. If you're good friends with the bride then yes, it's odd not to be invited. However, if you've barely ever had a conversation with her, you wouldn't text her or call her to see how she is or wouldn't just pop over for a coffee by yourself then it's understandable. Weddings are expensive and she may not have had it in the budget to invite a lot of plus ones, so it might just be good friends and family for the day. Don't forget, it's around £80-£100 to feed and provide alcohol for each guest (sometimes even more!), and it might not just be you that was cut from the guest list. Cut 10 people's partners who you don't really know and that's £1000 saved, which is A LOT of money if you don't have it! And really, it's up to the bride and groom who they have at their special day! Whether you go or not is entirely up to you, but the fact that she's even invited you at all should be an honour, not an expectation.

Yes!!