Trouble rotating image + other questions

[enginestar]

I rotate - manually using my eye to judge. Then I try to rotate again - the option for arbitary rotation is now missing. Why?

All I see now is 'Guillotine'

I'm using:

Image -> Transform -> Arbitary Angle (or something - I can't see it now).

What am I doing wrong?

What I would also like to do is... make a selection... and then rotate the image underneath... how can I do this?

ALSO... something else that has been bugging me... the ants... CTRL D should get rid of.
It doesn't
I don't want to get rid of the ants as such - just NOT have them there when I want with a quick keyboard shortcut.

ALSO... my Save for Web option has gone from the menu. I haven't updated my current version or anything. Where has it gone? It used to be there - even if the image was way too big - it was still there!

Is it the newer version of Gimp having different controls or something?

Thanks.