hi all just wat to know if the (look at the pic) threaded part that comes out from the hub for the wheel nut to screw onto & the locking pi goes through should be tight as in no movement or loose as in can wiggle ?

A little bit of movement is fine as it will tighten when you torque the wheel nut up

i have no idea how long ago the bearings & seals where replaced so i am going to change them all , also doing the front to

That threaded section can pull out the other side - it does wobble a touch, not to worry !

And has nothing to do with the bearing. If your concerned about the bearing move the rear caliper out of the way and stick the wheel back on, you will then be able to feel any play or roughness in the bearings.