Yes it is. Easy.
/ip firewall nat
add chain=srcnat action=src-nat to-addresses=10.0.0.46
This will srcnat all localnet ips as 10.0.0.46. I normally would use "action=masquerade", but since there are two ips assigned to WAN-0 (ether1), that is unpredictable.
ADD: This applies only if 10.0.0.46/24 is a "persistent ip" (you always get that ip by dhcp).
Alright, so I had already added "chain=srcnat action=maq..." and so on for what I thought was port 1 (of 0-4) only, but once I removed the static WAN ip, it looks like everything is working fine now.
So I have a dynamic WAN, and a LAN & WiFi with DHCP + NAT and all is able to get online now.
The last 2 questions I have are: can I set IP's based on MAC address? & how can i restrict access between the LAN and Wifi ports? or how can I allow traffic (for printing, etc) from the wifi port to the LAN?
I want to setup a hotspot but that can wait until I have more time tomorrow. Thanks again for all the help.