I can not find the answer to the following.

What do you advice about the maximum size of the database that can be imported ? Is there a sort of limit in which it works better ?

I found out that with 10.000 posts the proces takes a while and also freezes.
On parsing the images I saw it freezing at 7777 of the 11252 images.

I can imagine a limit and would like to hear your experiences with it.