You just answered your own question. RM is local WC is not.
You should also check out Simple Automation Rules for basic stuff, and Motion Light app, for well motion lighting. Both are built in apps you just need to install if you have not yet.
For complex stuff I have moved most rules from RM to Node-Red. I find it easier to create complex rules, and the processing of those rules does not impact hub performance. Plus we can share rules "flows" in NR. For me it is a nice balance.
As for dashboards I recommend using smartly to get a jump start. Once updated the dashboards run mostly local, and it's effectively a pretty 'skin' for the built in dash app (@spelcheck doesn't like me calling it an 'editor', but you can use it to edit stuff too 
) In full disclosure, icons/images/fonts are hosted offsite (AWS), but can be changed via CSS if you have the ability/desire to host your own images/fonts/etc. One of my dashes run 100% local, but it took additional work, and I will most likely go back on next update (was testing the ability).
You may also want to check out HubConnect while you transitioning, or if any devices are not fully functional in HE yet. Don't keep your ST device on that hub long term, or again you won't be local.
If your wondering how local you are, unplug your internet for an hour to see what works, and what does not.
Welcome to the party! 
