a123xxsp

It depends on OS distribution. Debian Jessie based images have only PHP5 available in the default repositories, and Ubuntu Xenial images do have PHP7.

I've created this script for building the latest version of PHP7 on any Debian based distribution:
 
https://github.com/kasparsd/php-7-debian
 
It worked great on Orange Pi Zero -- here is it running WordPress.

LTS (long term support) release, so you'll get security fixes for packages for a longer period of time: https://wiki.ubuntu.com/LTS Package base is newer in general compared to current Debian stable (Jessie). Once Debian Stretch is released this won't be true Ubuntu repositories have more packages than Debian

I used 'debian Jessie php7 armhf orange pi' instead (armhf to avoid tutorials that work on x86 only and 'Orange Pi' for obvious reasons) and 1st hit is https://www.symfony.fi/entry/install-php-7-on-raspbian-raspberry-pi#comment-2564656832 (though no idea whether the ARMv6 packages were used or compilation from source which I would prefer if I would still use Jessie... which I dropped since Xenial is way better  )

Looks fine.

Because your laptop has DVI-I output, which has analog signal in addition to digital. If it had DVI-D output, you would not be able to insert your DVI to VGA adapter: https://en.wikipedia.org/wiki/Digital_Visual_Interface#/media/File:DVI_Connector_Types.svg