Compilation question 64bit, 32 bit

[Jose Amengual]

Hi Guys.

The other day I install a server with jails with FreeBSD 7 32 bit in a  
64 bit capable processor.

After I install I start wondering some things that I point out here :

Any benefit to install 64 bit vs 32 bit with the purpose of use jails ?

Can I install a 32 bit FreeBSD and create 64 bit jails ? ( using  
ezjail or downloading the full 64 bit source to create the jail ).

Can I install 32 bit FreeBSD and then made a make world and change it  
to 64 bit ? ( is recommended ?)

Can I install a FreeBSD 64 bit and create 32 bit jails ?

I know that some questions are not jail related but because my focus  
is jail, I'm sending this email to this list.

Thanks in Advance.

Jose Amengual.