Tiling Tub Surround

How close to the top of the tub should I install my cbu? Should I caulk that gap before tiling? If so, should I use silicone or other? I have taped and thinsetted the corners - should I caulk the corners? When installing tile on the walls, how much of a gap should I leave at the bottom (against the tub) to caulk? Thanks in advance.

How close to the top of the tub should I install my cbu?

1/8"

Should I caulk that gap before tiling?

Yes

If so, should I use silicone or other?

Yes

should I caulk the corners when installing tile on the walls

Yes

how much of a gap should I leave at the bottom (against the tub) to caulk?

1/8"

Thanks in advance.

You're welcome.