For part of your question, I'm not clear on what you mean with "view." Do you mean just view device states but not send commands (e.g., "on" or "off") to devices? Or do you mean not able to modify the Dashboard itself (e.g., moving tiles)? Or do you mean just to view/see one Dashboard at a time and not the entire list except those you've specified? Any of these should be do-able if you use the right combination of options.
The second part of your question is easier to answer: you don't need the app to access Hubitat Dashboards. Each has its own local or cloud URL. If the device you're viewing them on is at home/on the same LAN, I'd use the local link. In the Hubitat admin UI, you can get this under Apps > Hubitat Dashboard by going to the "child app" for the actual Dashobard. Just use this in whatever browser you want. You can create tiles that are links to to other Dashboards, so if you just use the "main" Dashboard link, what it sounds like you might want should be do-able from there.
Beyond that, depending on what you really want, you may need to adjust the options for things under the "Advanced" heading in that same Dashboard child app--e.g., to disable tapping on "Dashboard" to get to a list of all Dashboards or to lock down the dashboard so you can't make changes when viewing it.