Do I still create a PR for the binding to be merged or listed so others can find the code on github easier? I am very new to github so not sure what options there are for what could be an low used binding and not worth building into Openhab 2.
If I read the small inline text correctly your binding uses some custom hardware to connect to devices already supported by another binding. In such a case you probably will get questions about the relation to the existing binding when you create a PR. I don’t know what the best outcome would be, but you can always create a PR to find out. But do expect a lot of questions.
Do I just keep offering the JAR directly as I am now?
The easiest and fastest way for users is to add your binding to the Eclipse Market place. That way users can install the binding with 1 click. providing JAR’s would require manual installation by the user.
I built the binding with the skeleton create binding script and choose “openhab” as the namespace? when the script was building. Does that mean it is not eclipse smarthome compatible and I should not upload it to the Maketplace as it is openhab2 only?
No. there is no difference as I’m aware of other than if you intend you binding to be part of the Eclipse smarthome core or the openHAB addons. In the first case use the smarthome namespace, in the latter use the openHAB namespace. There could be some version differences, but openHAB follows the smarthome version rather closely. Most bindings in the Eclipse Marketplace are developed from the openHAB use case, so that should not stop you from adding it to the Eclipse Marketplace