In relation to your 'second' interest, I can recommend the work of DAvid Brody and Linor Hadar on critical thinking. They researched a professional learning community of teacher educators who wanted to 'infuse' critical thinking in their teaching.
Building Networks of Practice, available at http://www.adb.org/publications/building-networks-practice specifies the essentials of virtual or electronic communities and gives advice on designing for performance, irrespective of the domain of activity. The article underscores the need to pay attention to forms and functions.
You might well and go right to the source. Etienne Wenger wrote the book(s) on Communities of Practice. Plenty of info here: http://wenger-trayner.com/
Greca, I. M. & El-Hani, C. (2015). Docentes e investigadores en comunidades virtuales de práctica para el desarrollo profesional docente y la mejoría de la enseñanza de las ciencias, Revista de Enseñanza de la Física,27, 1, pp. 7-18
El-Hani, C. & Greca, I. M. ( 2013). COMPRATICA: A virtual community of practice for promoting biology teachers' professional development in Brazil, Research in Science Education , 43, n. 4, pp.1327–1352
I'm not sure if I can help with this, but I've already employed a CoP facilitated by Facebook in English language practice for prospective teachers. If you go through the full text, you might find accounts on teacher's professional development compatible with this online community..Here's the full citation of my article:
Abdallah, M. M. S. (2013). A Community of Practice Facilitated by Facebook for Integrating New Online EFL Writing Forms into Assiut University College of Education. Journal of New Valley Faculty of Education 12(1), Assiut University (November, 2013), 581-650. Available on ERIC (ED545728) at: http://0-files.eric.ed.gov.opac.msmc.edu/fulltext/ED545728.pdf
Article A Community of Practice Facilitated by Facebook for Integrat...
Here is an older study that David Hammer and I did a while back. May be helpful Student Teachers on LabNet: Linking Preservice Teachers with a Professional Community https://www.learntechlib.org/p/94464
Vieira, R. M. (2018). As comunidades Online na promoção do pensamento crítico em Didática das Ciências (nº 1 da coleção Educação e Formação - Cadernos Didáticos). Aveiro: Universidade de Aveiro editora. (50 pp.) (ISBN: 978-972-789-538-0) (http://blogs.ua.pt/cidtff/wp-content/uploads/2018/07/201804_Cadernos-Didaticos_RMV_Comunidades-Online_PC_COMPLETO.pdf)