What are my options when replacing all house trim / molding / baseboards?
For the mill work outside of the cabinetry, you have two practical options:


Paint the trim. But note that oak has large pores, so you will see grain texture through the paint unless is was previously filled (which is unlikely).  This is probably your least expensive option.
Replace the trim. This won't be cheap. Trim is among the most expensive finishing steps, especially when you get into premium quality hardwoods.


This one isn't practical to do for an entire house, but it could be done


Strip, fill, apply lighter dye or stain. Again, oak has a very pronounced grain which can't be fully hidden easily. You can use a wood filler to level the surface but the texture will still have an 'oak' feel to it. This option is a ton of work even for a small project, but you can create a reasonable illusion of a different wood species in color, if not in texture. 


As for the cabinetry:

You could paint them, but I don't recommend it except as a temporary measure. Instead, apply adhesive-backed wood veneer to the cabinet boxes and have new doors made up in your preferred wood species. You'll have to be careful cutting and installing the veneer or it will look decidedly sloppy. Best to have an experienced professional do it. Here is a site that sells self-adhesive wood veneers. Here is a company that manufactures replacement cabinet doors. A quick web search will turn up many other companies that provide this service.