Today, a 3-day Microsoft workshop camp started (in Istanbul) and I talked to
MS guys a lot about licensing and I unfortunately didn't get good answers to
my questions.

There are some ways to license your SQL Server copy. Here they are:
- Server + CAL (User CAL or Device CAL)
- Processor Licensing.

If you buy a processor license for your SQL Server, then you don't need to
buy CALs for it. If you buy Server + CAL (User or Device) then you'll need
to buy CALs as many as your users\devices connect to your SQL Server
Instance and benefit from it. So, if you have a lot of users then it may be
better to buy a processor license instead of Server + CAL licensing. You
should do some math about it.

You can also find some useful information about basic licensing questions
and answers from this link:
http://www.microsoft.com/sql/howtobuy/licensing.mspx

I don't understand myself what is this standard edition "single user" but if
you tell us its price, maybe we'll have a clearer picture.

As to your second question, you should explain what you mean exactly with
the verb "distributes" in the sentence "... and distributes data to users".