Hi Justin,
As you know that meta title is very important on page factor so if you change meta title that could affect but in your case I don't thing it will affect too much because you are using very similar terms . *** CTR would also very important rule to improve ranking so write title in such a way that you can get more clicks.****
Second thing I would like to suggest you to use those keywords that currently in title you should place those keyword into web page content/ H1 tag where you find appropriate.
Meta description is not ranking factor directly but indirectly yes it is a ranking factor because a good meta description can increase CTR & if CTR will increase keyword ranking will improve. So you can change it to more compelling meta description in order to improve your CTR.
URL - You can change URL by using 301 redirect maximum link juice will pass to new URL.
You can follow this URL in case of Title tag
Firstst word in the title is the most important. Second word is the 2nd most important. The last word in the title tag is the least important.
Hope this helps.
Thanks