We’re so glad that you are enjoying this course so much! I will make my way through your questions in order given.
1: Yes absolutely, dried rose petal can be used to infuse into oil via either warm or cold method.
2: Shelf life for a salve and balm, if made well with little to no water in them, and stored properly (cool, dry and dark area), they can last 5 years or more.
3: Drinking lemon balm tea (it would have to be made with fresh lemon balm) could help prevent cold sores a little by easing stress and it does contain antiviral components that are active towards HSV, however it isn’t as effective as applying the fresh lemon balm preparation/essential oil (diluted in a carrier) directly to a cold sore as soon as the tingling sensation starts.
4: You could add thyme to this compress, but the lavender and chamomile that are already in it will help with the sinus congestion as well
5: Yes the plaster could be used for arthritis in the neck
6: Any heat resistant, pyrex glass bowl can work for this purpose.
7: The coconut oil salve recipe/instructions are found on page 352 in the bottom right corner of the calendula salve recipe page.
And with that, I hope this gets you going and you have a great time making lots of herbal preparations!