Do you feel you could use Tai Chi in a real fight?
I'll jump in on this. You can, but it's not as efficient as learning a combat sport where people specifically train to fight other people who specifically train to fight back.
It has some very useful ideas for self defense and it's a perfect relaxation tool as well.
A lot depends on how it's taught. I believe Nick Osipczak, an MMA fighter from the UK, is a tai chi person.