1. Upgrade not possible since the version number is not available in the list while upgrading it via third link. Check in the next version.
2. PHP REQUIREMENT LINK : https://github.com/slackero/phpwcms#server-system-requirements
3. We have change PHP requirement to 5.4 because it throws syntax error on PHP 5.3 while uploading any file.
(MIN PHP now 7.3.0 required since version 1.9.34 as /include/vendor/composer/platform_check.php throws error that Your Composer dependencies require a PHP version ">= 7.3.0" on login page)
4. We have set minimum MYSQL requirement to 5.6, due to the issue we have mentioned here https://github.com/slackero/phpwcms/issues/333 on MYSQL 5.5. Check if it works on MYSQL 5.5 in next version and change MYSQL requirement accordingly in info.xml.