There is a standard input component almost for any data type. For instance, text, number, checkbox, date, etc. Although you can configure them to be required fields, there is no way to make the screen components read only.
In this post, you can find a Lightning component that refreshes the page. You can call it as a local action from screen flows in order to refresh the page and see the updated data.
Although there are many global variables that give you useful information, there is no global variable about the user's device. Therefore, it is not possible to build a flow according to the user's device.
Purchasing licenses for multiple APIs and integrations can be too expensive. After having this issue for a long time, Salesforce finally announced Salesforce Integration User Licenses during True to the Core at TrailblazerDX 2023.
REST API can be used to launch autolaunched flows. Although you can perform most of the actions using REST API, in some cases it is a better practice to use an existing flow.