Since the IPv4 layer settings already take care of IP addresses that are present in the ICMPv4 layer (like for ICMP redirects), this section does not have any settings for this. Also, TraceWrangler will process quoted IPv4 packets (for Destination Unreachable etc.) just as another IPv4 layer, so the IPv4 parser will kick in again. This means that also quoted packets will be sanitized, of course.
Remove Ping payload: if you want to remove the ping payload, check this option. Otherwise it is kept, even if you selected "Remove unknown payload" in the general section. Well, it isn't unknown anyway, since TraceWrangler knows what it is, right?
Remove Packets with these message: sometimes it may be a good idea to remove certain ICMP messages from the capture file completely, e.g. those that indicate that a firewall or ACL has blocked access to a resource.
Recalculate CRC: this works just like the IPv4 setting. Since sanitization may lead to a modified ICMP layer, the CRC needs to be recalculated. But in case you want to keep bad checksums bad, TraceWrangler do it the same way as for IPv4.