Anno 1404 Top - Venice flop? (Installation problem)

As an avid fan of the Anno series, I think Anno-1404 for very successful.
Very high fun factor. Only the combat system of the soldiers ashore has developed negatively - as compared to the Voreditionen.
The graphics are great, service great, island worlds class.

For this reason, I have now bought Anno-1404-Venice-AddOn to use additional features can.
The more I was shocked that from Anno-Patch 1.3 (normal version) is no longer allowed to install the software Venice.
As a solution I found on the internet, that it should install the entire Anno-1404 new.
The installation instructions are classified by adventurous to halsbrecherisch.

This proposal I think is an insult, because you lose so all the success & Scores.
From a purchased software, I expect that the installation routine intercept such problems and existing Scores migrated.

My Conclusion:
Anno-1404 ***** - stars and highly recommended (even from the licensing system does not bother me).
Anno-Venice little recommended (installation is nerve-killing - even for a computer)

It seems to be so that you the Anno version at a later date may not change (Anno / Anno-Venice / Anno King Edition)
and you're set.