I can't say anything about older versions of Xerte as all I have done myself is install 3.0 for our users.
As said you seem to be hitting a problem with the 'template_id'. Because this fails you get the errors about 'dont_show_template'. I would suggest trying to create a toolkit again, and at the same time monitor the web server log files (personally I use 'tail -f' for this). In the web log file you should see a GET for a URL with 'edithtml' in it. It should look something like this:
"GET /xerte/edithtml.php?template_id=7 HTTP/1.1" 200
Yours will probably look a little different. It is the bit after the template_id that is causing the problem. The code is saying that it either isn't there or isn't a number.
