How can I fix pinewood flooring that got skewed after oiling?
First thing is to try and remedy the situation. Adding finish to one side has caused an imbalance in the woods ability to absorb and release ambient moisture, causing it to twist.  If at all possible pull up the offending members and oil the underside as well to help mitigate this affect. 

Once that's done reset your base moulding by shooting finish nails into the studs where applicable. In the areas with the cement wall, use a quality construction adhesive and (if possible) spring board the trim in place off the opposing wall until the adhesive cures. 

Otherwise try a combination of adhesive and double sided carpet tape to secure your trim. Hopefully the tape has enough oompf to keep the trim held down and there by keep the flooring where it belongs.  Cheers!