PHP7 compatibility with WP Engine hosting

Hi,

this site is hosted at WP Engine, where I can have it transferred to PHP7. I ran a diagnostic plugin to prepare that and for WPMU it came up with this error message:

FILE: /nas/content/live/chrisbizz/wp-content/plugins/wpmudev-updates/template/support-system.php
--------------------------
FOUND 1 ERROR AND 4 WARNINGS AFFECTING 5 LINES
------------------------
77 | ERROR | Extension 'mysql_' is deprecated since PHP 5.5 and removed since PHP 7.0 - use mysqli instead.
313 | WARNING | Function name "__render_list" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
334 | WARNING | Function name "__error_reporting" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
376 | WARNING | Function name "__value_format" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
390 | WARNING | Function name "__const_format" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
-----------

So my question is if your products will run OK with PHP7 - or should I avoid doing that?

Tx & rgds - Chris