hi fplolz,
i think you should try and sort out want you really want. the manual configs on the rc.d (including the the dhcp option) are usually best for servers where you need the connection before a user logs in or for connections you want to be available for everyone else who will login on the computer. you have two options here, the basic network service or the profiled network service.
network manager and wicd settings take effect after a user logged on the gui, so the implication you have to watch for are unreachable services (like ssh).
from my experience with networkmanager is that even if you set rc.conf configurations on an interface, it will muck them up leaving the routing screwed up. and on what i'm reading about wicd, it shouldn't :-) that might give you the best configuration you're after, static info for wired connections on rc.conf and dynamic info for wireless connections on wicd.