this means only binary file can be delete ? but binary files here means content URL?
I don't think alfresco binary files can be/ should be remove in anyway, right ?
Following this picture:
Everything you have inside of contentstore.deleted/ folder (all bin files) you must delete it: or manually, or with a cronjob in your OS, or using that url I've provided you. Everything you have there, you won't be able to recover anymore, means, you won't be able to see them or even they don't have anymore metadata associated. In fact, this task is something an administrator muts do it. As soon as you delete a file, after 14 days will be move to contentstore.deleted and you won't be able to do anything else with it.
I'll recommend you to read this post for more info about this process.
You have more information here, here and here. <-- and much more topics but I think it's ok with these ones.
BTW, what type of cache/files can be remove regularily ? is the purging cycle customrizasble ?
Related to cache, check the default cache configurations (in caches.properties from Alfresco source code on SVN mirror) and reduce the maxItems value. Here you have an example of this file, but I cannot confirm if it's in the same path or have same values in your installation (because yours is an old version).
the link you sent me seems for Alfresco One version 5.0 or later, I assume the alfresco community 5.0 is Alfresco One version 5.0 ?
No they are not, but in general for both versions apply same documentation (except for those modules/functionalities you haven't in Alfresco Community).
Let me know if you have further questions.