just ordered an o2 xda exec. some newbie questions

[ThatGuyFromOutWhere]

hi all,

i've just ordered my first smartphone, the xda exec (didn't know it was universal until after ordering), which i should receive monday.

i've got a few questions.

1. is there any recommended brand/size of sd card?

2. any must have software/accesories? i plan to use it mainly around the house.

3. is it relatively easy/cheap to use the exec for car based sat nav?

4. what is the screen like for watching movies?

5. i've got a motorola hs850 bt headset, will this work fine with the exec?

thanks for any answers left.