Updating to Version 4.9 and Adding checks from Front End

Hi there.

I haven’t updated to the latest versions of WordPress and Fundingpress because the client is currently testing the site so there a few updates that I haven’t done yet to avoid and disruption in their testing of the site.

1. Is updating the version of WordPress to 4.9 without updating the theme okay to do?
2. In the updates mentioned on Themeforest, it says that selecting check payment method can be done through the front end
– Added checks in front end
/funding/tpl/f-project.php

Is it sufficient to just replace the file or add the code related to checks from the updated file (f-project.php) into the old file?

Thanks!