The worst wedding I went to was a mid afternoon wedding that didn't serve food until 8.30 pm. They did bring lovely canapés round before the service, but there weren't many (and at that point people thought they were getting a sit down meal as there was a seating plan). People were really hungry before the food came, and even then it was a mini burger and a tiny cone of chips, so not filling. By ten o clock people had paid for taxis to bring them fish and chips from the chippy in the next village, or even given up and left.
Another bad wedding was a rich bride and groom that booked a fairy tale castle for their wedding that people had to book rooms for the whole weekend at £140/night. They then added a cheesy poem with their bank details so people could wire money instead of presents and also expected us to go to expensive foreign stag/hen dos. It would have cost us about £1500 to go to their wedding so ee declined everything.
OP gaps are OK as long as people know and if they are already there you can provide your own small buffet type food. We had a very small number of people at the daytime ceremony and went back to our house for photos (where we live is open countryside and very pretty, whereas where the registry office is wasn't nice outside) and a meal for the 25 guests then a huge evening reception later on. I decided on that partially because of cost, and partially because I'd been jilted before a wedding with an ex and really didn't want a big wedding the next time. A lot of friends really wanted to come to the ceremony, despite knowing there wasn't a daytime reception, just a meal with close family and witnesses. I put up a large gazebo in out garden, bought lots of champagne and made a buffet from M&S bought finger/picnic food. It was enough for people to graze on for a couple of hours while we did photos. I paid my friends two teenagers to pour drinks and lay out all the food and plates. It was very informal, but worked well.
By the way, I'm perfectly happy with just an evening invitation (I find the ceremony and speeches quite boring, I like seeing the brides dress and the party bit. I don't feel second class - these are often friends that aren't close friends, I feel pleased to be there at all.
I'm also perfectly happy to pay for drinks, I don't think I've ever been to a free bar wedding.