Finally there is web part allowing site visitors to add new records to selected custom table thanks to you :) However, I have checked your web part code and settings and I can say (as far as I’m concerned) that SiteName property does not take any effect in your web part. This property is propagated through CustomTableForm control to BasicForm and used only is special cases (for example when uploading files with file uploader form control [custom tables do not allow you to upload files by default] etc.) so it might be confusing for customers why they should set this property. Also, I would definitely check for emptiness (null) of DataClassInfo object on line 111 before accessing any of its properties.
Anyway, good luck with your implementations and thank you for participating here.