I'd replace the junk components as Ultegra stuff goes on sale (always does) and keep the 105 stuff until it wears out. Seriously, it ain't that different and it'll cost a lot to do it. If you ride/race as much as you say you will, you'll need new stuff eventually. Replace it then.

Unless you're rich. In that case just Ebay the Dale and replace the bike. And buy from a mfgr that doesn't spec production bikes with no-name calipers, seatposts, stems, cranks. We all know who they are. It might look like a good price, but once you get done replacing the above mentioned components, you've spent a pretty penny. And nobody will pay you more than [enter small #]% of it's orig MSRP, no matter what you've done to it.