I was thinking about the knock on effects if the Titanic sinking in 1912 is avoided. Maritime safety regulations might not be updated, and lifeboat rules not changed. Alot of wealthy influential people who died to let women and children off would live and might change history. James Cameron's black sheep hit wouldn't come out.
To be clear though, I believe if it did not sink in 1912, it would sink in 1914 or 15 by U boat because like other liners, the British would probably use it for munitions or troop transport and it would become a target.
She has a good chance of surviving ww1, she's quite well designed to take any damage from torpedoes or mines provided her watertight doors are closed. Britannic would've survived the mine had she not had her doors open for a shift change, the damage the mine caused warping the hull enough the doors jammed open. Unlikely to sink from damage Lusitania sank from. If Titanic survives without any serious damage she might last as long as Aquitania if she isn't scrapped around 36-37. Probably in better material condition than Majestic (Olympic was in pretty solid condition in the mid 30s) so might survive as a troop transport or cadet ship in Majestics place.
After that scrapped, very unlikely she survives as a hotel and judging by the horrendous state of the QM and the US today it may be the better fate.
Getting use out of Titanic might have been very valuable. White star was running out money because of high interest payments in the 20s and 30s. The line was essentially in a debt spiral more than anything else. The 3 Olympics started that (although IMM was using their position as owners to strip as much cash out of the company as possible so the debt spiral may still happen).
That is definitely true. There was 5,000 ships sunk during WW1 by uboats. I'd double or treble the deaths from those sinkings without the sinking of the Titanic.
IIRC Admiralty demanded lifeboat capacity for ships in its use. Not as sure for merchant ships but pre USW sub captains waited for crews to abandon ship before sinking so overall quite unlikely.
The survival of Titanic (lets say Britannic still sinks) means 3 ships capable of keeping schedule (Homeric was slower than Majestic and Olympic so screwed White Stars scheduling for weekly crossings) and allows them to be more competitive. However I believe Cunard got the majority stake because they had more ships on the books at the time of the merger so it depends when White Star scraps ships, unlikely to change with Titanic. Still have that clown in charge of White star in the late 20s it'll still be in a bad place though with better earnings perhaps.
Regulations will be toughened up after the Lusitania is sunk, so I doubt the casualties will increase anything like that much.
Difficult to say, Lusitania sank so quickly and with such a list there was never a hope of getting everyone into lifeboats. What you might see is regulations regarding collapsible boats, since the type lusitania used had to be assembled prior to launch, and try doing that on a heavily listing and rapidly sinking ship. Gantry Davits might last a bit longer but they only make sense on very large ships (redundancy) and were maintainance hogs