if the romans haddnt converted to Christianity, would the Christian world now be worshiping venus, mars etc et?

There were already non-Roman Christians before Constantine the Great decreed that Christianity would become officially tolerated and then the official religion of the Empire.

So, the Christians alive today would be worshipping pretty much as they do, but it's possible that some other faith would have come along to attract the attention of the Romans.

Judaism was a faith of much interest to many Romans, as was Mithrarism. Both of them had some requirements that made them impossible or impractical for many people to adopt them, but perhaps some other forms of them would have developed. I suspect that some type of monotheistic faith would eventually have ended up being the dominant religion in western Europe.

Yes. The main reason for people following a religion is because they learned to, and it's what's expected of them by the society they're in. If you're bought up in an Islamic society, you'd most like be a Muslim, if you're bought up in a Christian way, you'd most likely be a Christian, in the same way that if you were taught to believe in the Roman gods by your parents, then you would as an adult. If the Romans never were made to convert, then this learned behaviour would have been passed down through the generations, to the present day.

No. In the early 4th century, Constantine was looking around for something to reunify and revitalize a fragmenting empire. If it hadn't been Christianity, it might have been Sol Invictus, Mithras, Appolianism, Zoroastrianism, etc., but it would have been one of the more monotheistic type faiths from east that were all vying for adherents in an empire where Old Gods had done nothing to restore stability for nearly a century, and thus people were fishing around for something new that might bring back the Pax Romana of the Second Century.

mmm, good question.

I think you forget that the north came here and more or less took over. So in that regard maybe the Norsh Gods.

Problem is that one person can turn everything around, there is no way to know.

The answer is YES. Many would be worshiping the Roman gods and there would still be atheists saying they don't exist.

Jesus put the Romans out of business. It took a few centuries for the whole thing to sink in, but undeniably, christianity caused the downfall of that wicked empire

Yep! Mithraism was the biggest rival to Christianity, and it was a pretty close thing.

No. If God had not sent His Son Jesus the Christ as God in human flesh the entire world would be lost in darkness with no hope of eternal life. We would virtually be "dead men walking." Sin at the Fall made us "dead men walking." We needed a Savior, because there is no good in us. Our righteousness is as filthy rags. The only righteousness in me is Christ Jesus.

Very likely

@Pastor Bob "god wouldn't allow that"? Are you sure? He seems to allow all kinds of appalling things to happen, like famine, flood, disease, earthquake, infant mortality, wars...

But he'd have stepped up to make sure he gets his full entitlement of worship?

Nice god you have there...

Islam worships a meteorite