Is it bad to have so many meta tag keywords if you have a very broad website and they are all relevant to the site
Google doesn't use the keywords meta tag, due to past abuse this is obvious. But, in theory other search engine crawlers might use them to some extent, I would follow the w3c rules when using this meta tag.
If you do use them you should be using the keywords relevant to the page, not the whole website, id suggest about 5 or 10.