1 and 3. I would use the calendartool plugin or perhaps the 1T Day of Week plugin
- You will need to have multiple repeating groups or just one with some conditionals to change the datasource based on the conditionals which should be tied into your UX design.
Working with dates and time can be quite confusing. If you feel you need more detailed instructions feel free to PM about coaching/mentor sessions.
Also check out everything you can on the forum concerning how dates and times work, especially forum threads posted by Keith.