Airlines like China Airlines, Korean Air and Air France have far worse safety records yet none of these carriers change their IATA code. And both China Airlines and Korean Air are still going strong and profitable business entity.
The incidents involving those airlines (except for AF447) were from different era where people don't use #hashtag, retweet, forwarding the accident pictures in social media etc. The 2 incidents involving MAS caused the MH flight code to stick in the mind of people globally.
I am also in the opinion that changing the airlines's IATA code is not necessary but it seems that this pointer is being discussed seriously among (serious) A.Netters that I knew, so it must hold some weight. When Swissair evolved into Swiss International Air Lines, the airline code changed from SR to LX. So if MH is heading this way, the code does not necessarily has to start with the letter M.
As for marketing campaign and livery, I think these are a tad less important to what the airline needs to address in its first couple of months as a new co - corporate restructuring, route rationalisation, business plan. Once the fundamentals have been addressed then probably the livery and marketing tagline can be revisit.
My point on these 2 issues:
Livery - Should be mostly white. Something like JL. I am proposing an entirely white, with the wau logo just in red. It has to be entirely white to signify a new beginning, clean sheet, no corruption, less baggage, serious.
Marketing tagline - Should follow the current trend - catchy and memorable short words. E.g. Emirates' Hello Tomorrow, BA's To Fly To Serve. MH's current "Journey is made by the people you travelled with" is too mouthful, too long, very difficult to remember, too karangan Bahasa Malaysia.
To add one more to it:
Brand Ambassador - If MH is heading this way, choose the brand ambassador carefully. First of all, terminate the contract with that Australian tennis player no one knows about, what are you thinking? He/She should reflect the business plan - a new beginning, clean sheet, no corruption, less baggage, serious. Try to copy Etihad's coup of Nicole Kidman or Turkish Airlines' with Messi and Drogba, which I think is bloody brilliant. This person must NOT be a Malaysian. He/She has to be a global icon. My proposal - Louis Hamilton or Daniel Craig or David Beckham or Emma Watson [Hermoine in Harry Potters series] (she is currently dating Prince Harry, so massive future exposure here if she ended up as the newest member of the Royal family). British is best since MH does not fly to the Americas and the trunk international route is the Kangaroo Route.