I can't argue on that :) But also breaking the question to separately questions will not be the easiest to read on. This is my last comment in this topic.

@Mołot I didn't change anything at my question, i think the question isn't duplicate. The link you provide is just a part of the answer . A meaningful answer is to address all the little point of the question and not just a big part. This is a Q&A site but also a learning ground.

i'm glad it finally worked!

I think the professional think to do is to tell them to give you access to the ftp.domain.de so you can upload the site and after that you have to create the database.Import from the one you have now and change the settings.php to reflect the new db.

How you have done the migration?

If i exposed the form as block i don't get an ajax like behaviour. If i don't use the block everything work as it should.

You have a domain name (kantoorleenknegt.be) that have an index page with just a frame that show the real location of your site(/~leenkneg/). If you move your site from the /~leenkneg/ to the targeted domain it should work just fine!