User interface - Ctrl click
Click on URL opens URL in place, ctrl click on URL opens URL in new tab, for most browsers (Firefox and Chrome work like that, tested).
Click on message to be translated on translatewiki shows (actually loads) translation interface in a div (something that looks like hidden div), and that is ok.
What is not ok, ctrl click on message to be translated DOES NOT open that message in a new tab, but functionality is the same as plain click. To open message in a new tab, you need to right click message which will open context menu, and from it you need to click/select "Open in a new tab". That is annoying, and two different actions (click and ctrl+click) having same response is not logical - it is a annoying bug which needs correction. Thank you.
The old interface is unsupported now, so this is not going to be fixed. On the new interface there is no link at all, but there's a request for it at bugzilla:46955.