There is NEVER a such thing as a "tame" wild animal. Some are just less wild than others. There will always be a "what if" factor when handling the animal. As stated by Archie, these are apex predators. They are perfectly built to quickly dispatch prey.
As far as your queries on handling, you must be careful. While all crocodilians are individuals and some respond to handling differently than others...NONE of them enjoy it. Handling too frequently (or at all) can be very stressful. Crocodilians are largely HANDS OFF animals. The only times they should really be handled are during cages maintenance or veterinary checkups. Beyond that, it is highly advised to leave them be. It is better for the animals and safer for you.
While I was only generalizing when stating "2 years compared to 10 years", these animals will last MUCH longer than that. Do you live in warm climates year round? If you're up north...you can pretty much forget keeping that animal for that long of a time period. These animals get too large for most people to be able to provide for them long-term in northern climates. I'm not stating that it CAN'T be done, but it will be VERY expensive and VERY difficult.
Chris
-----
My Website
www.herpfanatic.com