The first TRACER article in English is still under publication. Depending on your referencing style, you can adapt the following:
Büchler, M., Franzini, G., Franzini, E. Bulert, K. (2018 forthcoming) ‘TRACER - a multilevel framework for historical Text Reuse detection’, Journal of Data Mining and Digital Humanities - Special Issue on Computer-Aided Processing of Intertextuality in Ancient Languages.
Yes. As per TRACER’s Academic Free License (see Copyright), you’re allowed to repurpose the source code as long as you credit the source, share your code in a similar fashion and don’t financially profit from it.
The www.etrap.eu website always lists upcoming tutorials a few weeks in advance. These are typically run during conferences or summer schools.