crack in firewall

[Torinoman]

So I found some water damage and surface rust on the driver side floor and fire wall of my Torino so I ripped out the carpet and all the old insulation. When I started removing the rust with a wire wheel I found a small inch long hairline crack next to the column support.

I don't really have the means to weld it up so can I just seal it up and pray for the best or should I find someone to weld if for me?

Also after I got most of the surface rust out there are some areas that are more pitted than Edward James Olmos' face , should I worry about that?