Got as far as sanding my 80 year old pine floors and discovered severe
pet stains. I really don't know what to do in terms of finishing.

1) Should I use a darker stain to blend in the pet stains?
2) Do I need a pre-stain conditioner since it's pine? I've heard that
old pine doesn't stain blotchy like new.
3) What about polyurethane coats? I've heard that even if you want a
satin finish the first coat should be glossy because it's harder.

Thanks,
Lauren