>>Such as what would have happened had First Officer Murdoch not ordered reversal of the engines, would she have made it around the iceberg?<<
Don't know. The problem here is that while the order may have been given, it's questionable as to whether or not it was carried out until after the collision.
>>If she had a double skin would she have survived? <<
Maybe. A double skin may well have confined the flooding to a specific area and prevented the foundering of the ship. The problem here is that with all the flooding confined to one side, the ship would have developed a substantial list that would have prevented launching the lifeboats on one side. This would have made for a really bad day for a lot more people had the damage been non-survivable.
Bear in mind that we're not necesserily talking about exclusively side damage. In all likelihood, the ship allided with a submerged ice shelf or ram which would have done substantial bottom damage and this certainly would have been a factor to be reckoned with.
>>The one question that has always dogged me is that if she had been put hard to port, would the rudder have been more effective given that there would have been the additional wash from the center screw, or what would have happened if in addition to using the rudder to port around the iceberg her outer propellers were also employed, one going full ahead, and the other going full astern to aid in the turning manuever?<<
An interesting question, but the problem here is that there just wasn't time to do any sort of fancy work by...say...reversing one propellor and leaving the other going full ahead. Unlike some modern ships, the engines could not be directly controlled from the bridge. Orders had to be sent by way of the engine order telegraph and men would have to have been on the throttle controls to work them. When entering port, people would be stationed for that sort of thing, but out in the middle of the Atlantic, they wouldn't be. Since radical manuevers are not routinely expected when way out at sea, there would be no reason to have everybody on station and ready to go.