1. We rename admin folder as it is strongly recommended to do so and it is mentioned at the last step of installation. Also we do not save admin_folder name in install.xml because we do not want admin url to update. (Added since 8.0.5).
2. Keep default values in Genreral Settings.
3. We have set PHP requirement to 5.5 because since version 9.0.0 script uses PHP 5.5's syntax.
4. We install with non-sample data(So keep Fill the database option : 'No' while manual installation) and we have removed sample data option from install.xml, Since sample data has issues while loading some frontend links,after renaming admin folder(in manual install as well). 
5. PHP REQUIREMENT LINK : https://github.com/advisto/peel-shopping#ce-quil-vous-faut