I tried a small instance on Azure, similar CPU and RAM. Discourse’s setup didn’t like less than 2GB of RAM and went ahead to create a swap file. It didn’t happen when I tried the next size up which has 2CPU and 2GB.
I can say Discourse runs like a speed demon on 2 CPU and 2 GB RAM on my small, light forum similar to yours. The smaller size VM should not give you a problem except maybe during installation.
Also using 2 CPU when rebuilding Discourse just takes forever… Like 15-20min or more. So if you are just playing around and trying out plugins, I suggest you go with a fast CPU setup. More expensive yea, but you’re likely to use it only for a week or two to get the setup down.
Then just downsize it back to small. Remember, everytime you change plugins, it is a rebuild. The waiting can be frustrating.