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This is a good and common question. There are two reasons why you would want to keep the 301 redirect in place

1. Usability: Users are still trying to reach this now defunct page
2. Inbound Links: There are external links that are pointing to this page.

The best thing to do is first narrow down the pages for which you have no reason to keep 301s in place. Open up your analytics platform and look to see which of those 45K pages have received no traffic in the last 30 days. Then use a tool like Open Site Explorer or Google Search Console to see if any of those 45K pages have inbound links. Chances are, most of those pages neither receive traffic nor have inbound links. Go ahead and drop the 301 redirect for all of those.

Then, prioritize the remaining pages. The ones with the most links and most traffic should probably retain a 301 redirect for the long run. Those near the bottom you might choose to drop.

Finally, with that many 404s, make sure that your 404 page is useful. Create a custom 404 page that helps direct users to their correct location or provides an easy search mechanism to find it themselves.

Looks like it is just missing a trailing slash past the domain. The profiles are working, just the link itself is incorrect.

The appropriate solution in this place would be to employ the hreflang tag to related the two geographically separate sites together. However, before you take that step, I would look to make sure the previous SEO company which created the .com did not point any harmful links at the .com domain which would make it inadvisable to connect the two sites together. Use OpenSiteExplorer to look at the backlink profile and use Google Webmaster Tools to authorize the .com site and look for any manual penalty notices. If all looks clear, go ahead forward with the implementation of the hreflang tag.

Good luck and feel free to ask more questions here!