1. The Small-Enterprice-Edition (SME) can be accessed via a Web-Browser ( I read a plugin is needed for IE). Does it matter from where the Qlik-Site is accessed (as long as the log in information is correct (25 users)) or is this limited to 25 physical computers instead of 25 users?
Plugin is required in case you need to view it on IE, You can avoid it Qlik has Ajax ZFC client that does not requires you to install plugin.
The limitation here for SBE is it supports 25 Named cal and 100 Doc Cals.
Have a look at attached document for more info on server types.
2. I read the SME costs 6500 Euro. I guess an actual server is not included within this cost (its just the software). Since Qlikview seems to consume a lot of RAM, what do you guys think should be invested into a well performing server? Or are there even any specific suggestions? ((We work with moderately big data))
This thing will completely depends on Data volumes you have.
It depends on several other factors as well Like no of users accessing application Design complexities and e.t.c
There are several documents available on community that demonstrate how to size your server.
3. At one place i read LDAP authentification for SME is possible, at another source i read it is not possible. So - can you guys help clear this up for me?
With SBE the only security you have is NTFS/Active directory.
SBE does not supports LDAP integration.
Enterprise level Integrations are only possible with Qlik Enterprise Editions only.
4. Is it possible to grant rights or create roles? For instance a user of the role manager should see more content than a user of the role standarduser. Is this included?
Yes, You can hide sheets/ Tabs based on user logged in.
5. Is it possible to encrypt columns (eg. MD5 /SHA2)? Any chance of mixing this up with the user permissions? For instance a manager should be able to see the names of other users in cleartext, while other users only see the encrypted MD5 oder SHA2 string.
You can encrypt data but it will be encrypted for all.
I don't think you can have partial encryption.
6. Any other reason to take an Enterprise Edition over the SME if generally 25 users would be enough?
I believe this is answered above and attach document will help you regarding the same.
Hope it helps
Regards encrypting columns for some users, there a several ways to achieve this
You can load the data twice, one a plain text field and again using a hash function to pseudo encrypt the data. Then section access can exclude the plain text data from those who do not have permission to view it.
Alternatively you can just use section access to omit the data field for the users who do not have permission.