1. The classification of the main typeface used in this poster is sans serif
2. There are different strokes being uses and also it is very clear on what is being emphasized and what is most important.
3. I would say that the typeface is appropriate to the material. For example 2 and 3 there is a lot going on with some fonts that are bigger.
4. I think that the background works well with the type, since the colors that are being used are light colors it makes the text pleasing to read.
Clearly described, Jessica.
For number 2, the word “weights” rather than “strokes” better describe the type.