1) Basilica was courthouse not pagan temple.
2) Building Churches in shape of Cross is pagan practice?
3) Christians developed it. They used some elements from Greco-Roman basiliacs, but it is essentialy different.
4) From when Ancient Slavs=Ancient Greeks+Ancient Romans
Svetoslava, there is nothing pagan in this style of architecture. And this churches were build 100 or 200 years ago. By Christian Slavs. If you agree, last 1000 years waste majority of Slavs are Christians. Being woden or Slavic does not qualify it not being Christian.
to get on topic: did they built cathedrals and then blow them up?
Emperor Alexander I decided to build Cathedral of Christ Saviour "to signify Our gratitude to Divine Providence for saving Russia from the doom that overshadowed Her" and as a memorial to the sacrifices of the Russian people during Napoleonic war. But building stated 1839 Cathedral was consecrated 1863, and Emperor Alexander III was first to be crowned there.
Stalin demolished it.
On December 5th 1931, by order of Stalin's minister Kaganovich, the Cathedral of Christ the Saviour was dynamited and reduced to rubble. It took more than a year to clear the debris from the site.
In February 1990, the Russian Orthodox Church received permission from the Soviet Government to rebuild the Cathedral of Christ the Saviour.
A construction fund was initiated in 1992 and funds began to pour in from ordinary citizens in the autumn of 1994. Rebuilding was finished in 2000.