Most modern bike shoes are made of Lorica or some other kind of "fake" leather. Don't think Lexol would hurt them but not sure either. I just wipe mine down with a damp cloth and mild soap if they get dirty.
Have only used a shoe tree to try to stretch a snug pair of bike shoes but don't think a wooden shoe tree will hurt anything. Always pull out the removalble insoles at the end of a ride and let the sweat dry out. I am impressed with how long cycling shoes actually last. Thought I would be looking for a new pair after a year or so, but the Nike shoes look almost new into year #4.
Really like Nike cycling shoes but I would not pay extra for a chip in the shoe. Cell phone works well for emergencies.