>>I like this theory of suicide.<<
Then you have a problem since this proposition can barely be described as a theory. It falls squarely in the realm of speculation which has scant evidence to support it and quite a bit to contradict it.
>>well let's think here. he ran the ship at full speed, even when it hit.<<
As pointed out, this is simply not true. The best the ship was known to have done was 78 RPMs on the engines and Titanic was capable of doing better. They may have intended to try a high speed run on the 15th, but if they did, a frozen roadblock canceled the plans in a vry permanent fashion.
>>he was going to retire,<<
A questionable premise.
>>... meaning he could be forgotten in history, and he had iceberg warnings throughout the ill-fated trip.<<
So he was going to ensure his place in history by...for all practical intents and purposes...wrecking a $7,500,000 liner and killing up to 1500 people which would mean he would face criminal charges of barratry and manslaughter if he survived and being remembered as a homicidal maniac if he didn't?
Riiiiiiight....suuuuuuuure he would.
>>and he had iceberg warnings throughout the ill-fated trip.<<
And so did everyone else. Information that would have been badly dated by the time he got to the positions in the reports. Perhaps you forgot to question some sailors and deck officers about their attitudes regarding reports. Well, since I'm a retired sailor, you're in luck.
We regard such reports as exactly that...reports...useful, but only insofar as any such gives us a heads up on places where we need to keep an extra vigilant watch. We know that icebergs move with the current, so the watch team is alerted and the lookouts are brifed to be on the lookout for ice. That's exactly what happened on Titanic. The watch was alerted, and the lookouts were given special instructions to be on the lookout for ice.
They still managed to hit one, but they tried very hard not to!