The unofficial Honda Forum and Discussion Board Forums For Honda automobile and motorcycle enthusiasts. - 99 Civic Lx Rust, opinions needed, have pictures

I have a 99 Civic Lx with some rust. My question is are these repairs that need to be done immediately? The major one is this:

http://imageshack.us/a/img819/4397/7s3d.jpg
http://imageshack.us/a/img33/1052/40dq.jpg
http://imageshack.us/a/img189/2518/ltvw.jpg
http://imageshack.us/a/img802/2976/pocg.jpg

These are pictures of the rear bumber, from the frame/unibody. It had a fender bender a long time ago and that probably did some cracking to the welds or something.
It's about $136 according to this online store

http://www.hondaautomotiveparts.com/...atcgry5=BUMPER

Other rust concerns I have:

[IMG=http://imageshack.com/a/img593/5417/t6qg.jpg[/IMG]
http://imageshack.com/a/img17/6651/iapt.jpg
http://imageshack.com/a/img593/5417/t6qg.jpg

This is some part above and beside the oil pan (yeah it's leaking)
http://imageshack.com/a/img844/888/09zz.jpg

I think this is the subframe

http://imageshack.com/a/img203/9500/lbha.jpg

I have noticed some nuts and bolts rusting out under the car, bolted into the frame. Should these be changed before it spreads, breaks, or gets rounded? They seem to be good enough to be torqued out.

Note: The car was rained on before I got it into the garage. I don't know if those wet spots are normally okay to be wet.

Thanks for looking, and I'm looking forward to replies!