All your issues on your website are coming from incorrect php settings on your server.
I can suggest some changes you can apply .
1) Lower your php version try with a 5 version temporarly , this should fix some errors , like purity template to be removed.
2) Temporarly uninstall your admintools extension
3) Remove all not needed tables from your database - leave only the ones starting with jbg25_ prefix
4) Remove all the not needed extensions tables from database - ( table jbg25_extensions )
Anyway these errors are not coming from Joomlart template JA_University - i also can suggest to hire a sysadmin to have all these settings fixed correctly.
Hope it helps