Meta keywords doesn't harm your website in any which ways, though it doesn't even help  you in gaining rankings in Search Engines,

Matt Cutts says "It's possible that Google could use this information in the future, but it's unlikely. Google has ignored the keywords meta tag for years and currently we see no need to change that policy."

However, there are other search engines and directories that use the keyword meta tag. For example, Yahoo! still uses it

Hi,

Canonical tag is only required if the search engines are able to access both the pages. There is no need to apply canonical tag as long as the duplicate pages are being redirected to the new/original page.

As you've specifically mentioned to Google that these page do not exist anymore and I've created a new page for all these pages, and now you want your visitors/search engines to visit the new page which doesn't have any duplicate entry.

Canonical tag only works if you're running a

• multilingual website or
• you're using some query strings for tacking purpose
• you've multiple copies of the one page and those page can not be deleted.

If you're sure that after 301 redirect there will not be any duplicate entry for the page, you don't need to apply canonical tag.

Hope it helps