Change get size output and goto other tab?

[Andreas Jantvik Gyllenlid <ajg inbox com>]

Hi,

I want to be able to get the size of directories - and I know how to do
this (F9-letter C-Shift+i). This outputs it all in bytes, however. 
It would be a lot more understandable to me if it outputted it in
megabytes instead...
Is there a way to change this?

Also, is there a way to "cd" to the location of the other tab?
I tried making a costum command "cd %D", but that didn't work.

And finally, can MC remember selected directories even though I enter
another directory? (file manager Gentoo can do this)
Example: I select a lot of folders to copy to my mp3-player - then I
feel I have to check the contents of one of the folders. I enter into
the folder - and when I come back out of it all my previous selections
are gone! I have to select it all over again...

Thanks!