I have a text with a linebreak, how can i add this in Trema?
Using the edit action (Ctrl-Alt-E) in the table tree view brings up a dialog that allows to enter multiline strings.
Can I put HTML Tags into my texts?
Yes, use the text editor in the table tree view to enter the HTML Tags. Trema will escape them so that they don't break the xml.
Should I escape trema text resources for a given output channel (e.g. HTML)?
No, this is generally not a good idea, since you never know, where these resources will be rendered to (e.g. a HTML-escaped text might not work when sent in the txt-mail and so on...). Make sure to enter plain vanilla text in trema and encode it correctly on every given output channel, if needed.