Been there done that.
Other than that line, everything up there is steel line. Usually incorporated into the tank itself.
There is a spot on the top right that water can collect and rust through, also the seems on these tanks are not good. Mine had about 3 different leaks when I removed it. There is no way to deal with it without dropping the tank and odds are you need a new one.
Trust me on this, if you are going to drop the tank, buy a new one to put back in. I found mine for $145 shipped 2nd day air.
Why new?
Because dropping the tank is the one of the 3 most difficult things you will ever have to do on this car. The other 2 are rear subframe, and timing chain housing. Oh and be sure to buy a new crossover tube, the old one will probably not come off.
How much of a hassle is the tank....
Put it this way, if my best friend called asking for help, I would probably have plans.
Quick run down.
Remove battery
Drop exhaust
Drop heat sheilds
pull driveshaft
check C.S.B. and guibo, also buy new Guibo bolts, DO NOT re-use them
start disconnecting lower hoses
pull rear seat
pull covers
Take pics of connections, draw diagrams, etc...
pull pump
Drop tank, have a buddy on one side, and use a jack on the other. Lower it part way down, and have the jack man go into the car and remove the last hoses.
Reverse for re-install.