You could certainly set your checks to run every minute. How many checks and what checks would determine how many resources you needed to do this. Passive checks could certainly help, as could using an offloader such as mod_gearman. (See also the quote from our roadmap below)
As for development, I don't think what you are looking for is actually a plugin. Our plugin documentation is at
http://nagios-plugins.org/doc/guidelines.htmlIt sounds like what you want to develop is a different front end. I don't think we have a guide for that. I'm not really sure the best place for a feature request on that. The best option might be to just wait:
Nagios Core 4.3 is currently scheduled to be released around April of 2017. This will primarily be an enhancement release. Some of the changes projected to be in this release are:
Native remote workers
Updates to the Nagios Core GUI
Performance enhancements to the Availability Report
Performance enhancements to the status.cgi
Another option my be to talk to the developers of pnp4nagios or NagVis or one of the 3rd-party graphing tools already out there.
You are also welcome to get involved with development at
https://github.com/NagiosEnterprises/nagioscorePlease let us know if we can be of further assistance.