Dasboards with no config options

Our customer Service Agents want to use kibana dasboards. We don't want that a Agent can Chance Anything in the dashboard (except the 'time')
Is this possible?

Not currently no way of doing this, please check out https://github.com/elastic/kibana/issues/3904 for future functionality.

Hello, I've the same problem and I'm experimenting with modifying the Kibana interface itself.
You can do that (experimenting, I mean) going on GitHub, downloading the Kibana package, installing it as stated on the CONTRIBUTOR.md file (be careful that you have to force the use of the proper version of nvm (eg. nvm use version) otherwise it doesn't work) and then you can start to try your changes on a stand alone kibana instance going inside the proper files (js and html), doing your modification and seeing them immediately on the browser (after F5).
Once you will be done you have to repackage Kibana and use the new package to production (but I'm not arrived to this step yet).

Said this, I have a problem myself: I'm putting together an interface that leave to the user the ability to change time (and in a restricted time range too) only BUT I, as "admin", need the ability to create/modify everything (in short, I need the standard interface of Kibana).
How can I achieve this goal? I'm thinking about having to instances of kibana using the same .kibana index on ES (and using, maybe, different listening ports (eg. 5601 for the user, 5602 for me) but I don't know how to do it... or is there some other solution?
Thanks in advance.

I just tested my own proposed solution.
I installed, on the same machine, another instance of Kibana (in a different folder) and configured, in the kibana.yml file, a different port (I used 5699) for the server and I left it to point to the same ES as the first kibana instance.
Then I started it and I have two kibana sites: one responding to myhostip (with no port, so 5601) showing the UI reflecting my modifications and one responding to myhostip:5699 showing the standard interface for Kibana4.

I tried to create new dashboards on the 5699 instance and they are reflected immediatly on the instance 5601.

So far so good, I have to put it a bit more testing in it but I think that this could save my day... and hopefully yours too.