It’s not super uncommon view here either. But I think the vast majority of users want to be able to control their home automation/get notifications from their home automation where ever they are in the world. And for those who are smart enough to know that they don’t want this, well they probably already know enough or have the skills to discover how to do it on their own.
But I think it is key to understand that the UIs for OH are just web pages. Even the phone and tablet apps are working through a web based REST API. So the answer to how to not have access over the Internet is t “just don’t do it.” You don’t have to do anything extra to prevent access from the Internet. On the contrary, you have to go out of your way to enable access from the Internet (e.g. create account on myopenhab.org and install the Cloud Connector binding, set up OpenVPN, ssh tunnels, reverse proxy with a port forward 
). It’s hard to write docs which basically say “to prevent X, don’t do anything.”
Absolutely you can do this. But all that will largely be outside of OH, or you will be running OH on each tablet and set up federation between them (that isn’t what I would recommend). These are full computers so they can run any program and they can interact with any hardware they have the ports or antennae to communicate with. But using a laptop as a tablet home automation touch screen is not common and a very key bit of missing information from your OP which probably was the source of some of the confusion. Most Android/iOS tablets or special built panels like MDAR mentioned are far less capable.
But with laptops you can set up SqueezeBox for full house audio, plug in devices to the USB ports, connect to BT, etc. HABPanel can be used as an audio sink so you can use just the web page as a TTS destination. But you will either need to find or write software that pub/sub between these panels and your main server, or actually run OH on these panels directly and federate them with a “master” OH. There are lots of ways to make this happen but the best choice.
HABPanel is just a web page. BasicUI is just a web page. The phone/tablet apps are just an app wrapped around a web page. And it’s a web page served up from one central openHAB server. How are you going to hook up a physical sensor or actuator to a web page? How are you going to get the sensor readings to all the other panels through a web page? You don’t. You do this through the server that is creating the web page.
You can have as many of these web pages as you want. So you can create one HABPanel view for the living room and a different one for the kitchen. But the actual logic, the actual communications to devices, the actual integration of sensors and actuators takes place on the openHAB server, not in the web browsers running on individual UI devices.
Absolutely. See Share Z-wave dongle over IP (USB over IP using ser2net / socat ) guide for one tutorial on how to do this. There are all sorts of other approaches. For example:
- zigbee2mqtt (Zigbee support)
- reelyActive (BT presence detection)
- FIND (WiFi presence detection)
- NodeRed
- lots of other technologyx2mqtt services are in work out there on GitHub
- My own GitHub - rkoshak/sensorReporter: A python based service that receives sensor inputs and publishes them in various ways. which does BT scanning, executes command line scripts, and lets OH command GPIO pins or subscribe to sensor readings from sensors attached to GPIO on an RPi.
But this is still integrating “remote” devices with a central OH server. OP appears to be under the impression that the UIs for OH are more than what they are.
I would be remiss if I didn’t offer my standard advice for all new users who are looking to tackle a big project like this.
-
If possible, error on the side of automation without UI rather than automation with a UI. It’s home automation, not control. OH is a big event processor. It should just do what it does based on what it knows at the time and the events it receives. It’s so much better when the lights come up when you enter a room and it’s dark than to walk into a room, walk over to a panel, and turn on the lights.
-
Consider the failure modes. To paraphrase my favorite joke from Mitch Hedberg, “You should never see an escalator out of order sign. Just escalator temporarily stairs, sorry for the convenience.” Build your home automation so it is intuitive to children and guests and when something fails it’s designed to still be usable in a diminished state for it’s intended purpose. If OH is down, you should still be able to turn the lights on and off. Build escalators, not elevators.
-
Start small and gradually build up. No one who first gets into home automation has the knowledge necessary to make the correct decisions out of the gate. You want to fail fast and have the flexibility to pivot quickly and the only way to do that is to build your system gradually.