Hi,
If you could provide some more details of the setup ( network diagram, device details..etc)it would be better to assist.
However you can have the following points ensured..
1) For the BGP session to be able to establish across a firewall, you need to ensure that Port TCP 179 is opened in the firewall for the BGP peers.
2) You need to check the firewall for how ping is allowed in the policies.
3) IP Spoofing means, an ip packet is received on a interface, from where it is not supposed to be. Basically the source IP Address of the packet is checked to ensure that only known/valid addresses are coming via that interface.
Checking this would require a fair idea of your setup.
HTH
-VJ