Swap is easy, just create one swap partition with the first Linux installation and it can be used by the second. What makes it tricky, for example, is when you hibernate one Linux and then attempt to boot into the second. Since the second will also use the only swap partition, it is likely that the content will be overwritten.
With respect to Windows, it may be a good idea to install it as the first OS on the machine since else it will override grub.
For the /home partition you need to consider that some applications will store their config settings in your /home partition. So if, for example, you have two Linux installed, which both use Gnome or KDE, they may override their settings.
please try again wrote:
> You can share your /home partition with openSUSE and Ubuntu (I do with
> many distros). But you can not share your home directory. The easiest
> would be to use a different login name under each distro.
Another option, if you want to use the same username and uid, is to
create separate home directories and then link to shared content in
subdirectories (~/Pictures etc). That keeps the ‘hidden’ ‘.’ directories
Yes, that’s what I do (but didn’t want to start another boring explanation for a change). Actually I redefine the home base directory before creating users, so the home directories will be subdirectories of /home/$(lsb_release -is) or /home/$(lsb_release -cs) … or whatever. The syntax is different for openSUSE and Ubuntu.
No, just because of the many user (desktop and application) settings that might be different or refer to other files, include different paths, etc. The user:user structure wouldn’t bother - provided the user has the same UID under both. Btw I use “user:group” for all distros (many default to “user:user”).