I don't believe the tree needs to be outside or it will die as it sat around in the store for months, and it's been sitting in my window for about 6 months, so that would have been plenty of time to die but it didn't. It's doing absolutely fine. When I bought it it had half the leaves and branches. Since then it grew into this big bush. No leaves fallen off, nor any pests and diseases. It sat in my window thru the cold months and it didnt die.
So I would say that statement is false, but thank you for your opinion.
90% of the questions in the help section are about dying trees that are inside... you could be the exception but we'll see in a year or so...Btw, there is a huge difference between the store and our homes, but as i said, we'll see. Of course we only see/hear from people with problems here, the ones that are doing fine don't show up here.
Concerning your question about letting it grow or wiring: that is totally up to you really. If you like the hight it is now, you wire a bit and prune a bit, but the consequence is that it wont fatten up, or you let it grow, and start pruning and wiring later