If you choose systemd-boot, EOS will detect that the existing EFI partition is too small and create a second, dedicated EFI partition for EOS. If you choose grub, it will share the same partition. Occasionally, Windows will mess it and you will need to manage that. In some cases, it is just a matter of changing the default boot entry, in more extreme cases, you will need to reinstall grub.
Unless you need suspend-to-disk(hibernation), I would not create a swap partition. I would either use a swapfile or zram/zswap.