I'm new to the forum, and I've participated in answering questions and asking them. IMHO esl teachers are in general a poorly trained lot. I strive to develop my understanding of grammar, semantics, syntax and pedagogy in order to be effective as a teacher, and to make sure that the concepts I teach are accurate and useful. While I find the state of esl pedagogy woefully inadequate, I do hope that it will improve over time, and that I may contribute to such progress. I've searched for forums specific to teachers but have found none that are particularly useful. This is by far the best forum I've found to date and while I'm neither a linguist or etymologist, I certainly do qualify as an enthusiast. However, despite the fact that language acquisition is an accepted domain of linguistics, there is little to show of it in this forum. I do hope I will be welcomed.
It depends. English Language & Usage might be what you are looking for if you are interested in the details and nuance of the language. On the other hand, if you are wondering about how to effectively teach certain concepts or if you are seeking understanding of some of the aspects of the language that frequently confuse non-native speakers, then English Language Learners is a good fit.
There's no reason you can't frequent both communities, and I would encourage you to do so.
You might like to read my answer to a meta topic on the ELL site that I think is a good rough sketch of the difference between the sites.
Based on the following statements you made, I believe you will be quite welcome here:
I've participated in answering questions and asking them.
I strive to develop my understanding of grammar, semantics, syntax and pedagogy in order to be effective as a teacher
This is by far the best forum I've found to date and while I'm neither a linguist or etymologist, I certainly do qualify as an enthusiast.
That's really about all it takes as a foundation. The fact that you will be approaching the forum from the perspective of a language acquisition instructor should be no impediment, though there are some things to be aware of as you participate.
Feel free to also peruse other meta questions to see what kinds of discussions are carried out by experienced users on the site. The best way to learn is by looking at questions by experienced users and seeing how they contribute, as NVZ pointed out in their answer.
Ultimately, the best way to learn about the site is by participating and seeing what sort of responses you get from different kinds of questions and answers. Don't let one bad response to an answer get you discouraged about the site. Keep working, but try to learn from the feedback that you get each time. Considering that you've put this much thought into your participation already, chances are you'll be an excellent member of the community. To echo NVZ again, welcome to ELU!
I don't think that ESL teachers as a group will find major areas of disagreement with how semantics is treated on ELU.
How pragmatics is treated is more problematic, but that's hardly related to whether or not one has had ELU training: pragmatics grades into style choice and tends to be somewhat subjective.
But when one looks at grammar, one finds different schools of analysis members of which can disagree quite strongly. And as Quirk and Svartvik pointed out, educated Anglophones can even (and quite often do) disagree over the very acceptability of certain constructions. Claiming 'this is correct' is often an arrogation.
From previous conversations, I've picked up that there isn't a unified ESL approach to grammar (though some would like us to believe that there is – and possibly even believe there is themselves). A major problem on ELU is that some assume that the terminology / standards of acceptability / methods of analysis they have been taught are unique / universally accepted / unchallengeable / final (or at least post convincing-sounding answers as if they do). In scientific articles, definition of terms as used locally, labelling of hypotheses as such rather than laws, and attributions to those giving theories would be considered mandatory. And if a certain approach was required by some institution, opposing ones would be acknowledged and caveats attached to publications.
Welcome to the ELU family!
Check out the posts by of one of our best users, and you'll get off to a good start.