is there a plugin for notepad++ that allows for files to be run through a compiler for simple syntax checking? such as to catch missing ; or or non-matching brace counts, etc.?
Not tested myself, but you should be able to do this with the Run Command (F5) and a windows binary of PHP.
The command you most likely would want is as follows:
cmd /K c:\path\to\php.exe -l $(FULL_CURRENT_PATH)