1: Yes, you'll be able to choose the swap partition during FC3 installation
2: Most of the distros won't make any effort detecting other Linux distros, you have to configure the bootloader yourself, fortunately this is quite easy.
Install FC3 into your unallocated space again, pay attention when it asks you where you want to install the bootloader. Make sure you install it to the Partition Bootsector
, not the MBR(Master Boot Record).
I assume you only create a / partition on the remaining space for FC3 and nother else.
After installation finished and you reboot, you should still see SuSE's GRUB bootloader and you won't be able to boot FC3, that is ok, load SuSe.
Edit /boot/grub/menu.lst and add the following:
title Fedora Core 3
Reboot and you should see FC3 in your bootmenu, when you select it you'll see FC3's grub bootloader menu.
Besides the above method you can also directly add FC3's kernel in your SuSE's GRUB config file, therefore you don't have to go through GRUB twice.
Basically just copy the entries from FC3's grub config and add (hd0,2) in front of it, so it should look some like
title Fedora Core 3 2.6.8-whatever
kernel (hd0,2)/boot/vmlinuz-2.6.8-whatever parameters