The errors are pretty clear and straightforward. You might want to add use diagnostics; to the top of your Perl files to longer descriptions of the warnings. At least until you're familiar with the jargon.

Useless use of defined operator in void context at /path/to/user/readin_pagevars.cgi line 7.

defined($content); doesn't do anything. What did you want it to do?

Useless use of private variable in void context at /path/to/user/readin_pagevars.cgi line 35.

eval{$syscode2}; doesn't do anything. I think you want eval($syscode2);. Don't confuse eval BLOCK with eval EXPR. They are two completly different functions despite their unfortunatly identical name.

[ numerous other errors ]

You didn't provide the code that generated these errors, so I can't tell you anything more than use diagnostics; would provide.

And you really really really should be using an existing templating system.