1- You can make this jam without the jalapeño if you like. 1 Jalapeño with seeds is mild, add more to kick up the heat.
2- I ended up with 2.25 cups of liquid with one batch and had extra jelly as a result. If this happens to you, you can either add another jar for the remainder and process with the rest or not process the excess and use it right away.
3- Recipe adapted from this
guava jelly recipe