Hi @evzin
1. Yes, the multi-site license allows you to use the add-ons in all web projects you work on. You can also incude the add-ons within premium themes, however, this may change in the future with an introduction of a developer license.
2. Yes, all add-ons will recieve updates
3. ACF is required for the add-ons to function. Think of it as a limb needs a body to work.
4. Yes and No. The flexible content field can replicate all of the repeater field functionality except it’s user experience. A client will be much happier using the repeater field to upload images / files at it supports multiple file uploads / quicker to add rows. Also, the code is simpler in the templating.
5. You may us the message field to add HTML to the options page!
