I don't have a lot of time to post right now, but I do have my pfsense running through Virtualbox with no problems whatsoever.
My setup is 2 physical interfaces in bridge mode using AMD PCNet-PCI II type. I've tried all four types and these work best. If the only computer to connect to pfsense is your laptop, then I don't see why your LAN interface can't be host only.
My modem is in bridge mode and and the WAN interface is set to PPPoE. I'm not sure if you can do this with your wireless router, but if you can then it will make things simpler as pfsense will perform NAT and will get your public IP address instead of an internal one from the router. If you don't use it this way, then I'm fairly sure you will want to disable the NAT on your router or you will NAT on NAT
This will also mean that your router will not be connected to the internet when pfsense is not running, but from your post, the laptop is the only thing connected to the internet so that shouldn't be an issue.