I always love reading peoples first impressions of Waiting for Godot, mostly because it is so often “huh?”. Like you, no one ever seems to know quite what to expect, and any expectations they do have are always wrong (my own included). It’s what makes it such a fun piece of literature.
The way you summarised the play by saying: “‘Nothing happens’ in the play the same way one might proudly claim to be doing ‘utterly nothing’ all weekend.” Is such a spectacular way of looking at it and so very true. Their existance is what is happening, just like our more boring weekends.
I like that you identified a romantic relationship between them. Their relationship is literally the only thing driving the tale, as silly and ridiculous as they often are, and their different personalities are the only things driving conversation.