[gentoo-user] installing gentoo with a systemd profile

I am installing gentoo on a new laptop.  I am a gnome, hence systemd,
user.  I also use lvm (I have / and /usr combined on a non-lvm partition).

At the point where you choose a profile
(//wiki.gentoo.org/wiki/Handbook:AMD64/Full/Installation#Choosing_the_right_profile)
I selected
[5]   default/linux/amd64/13.0/desktop/gnome/systemd *

But now I get merge conflicts since I have sys-fs/udev installed.
I can't depclean udev.

Should I have just used the  default/linux/amd64/13.0 profile
and switched later after the installation is complete.

Fortunately, I don't need to used the new machine immediately so I don't
mind starting the installation over from the beginning

In a similar vein, my systems have PORTDIR=/var/portage.  Am I correct
in now believing that it is better to do the install with the default
PORTDIR=/usr/portage and then switching after the dust settles

thanks,
allan