let's relegate the double vs. triple debate of principles to the search function, it's raged here before....

however:

yes, you can go to 29 on Campy without needing a long cage der - the chain wrap capacity is sufficient.

In fact, you also can on Shimano, although the Manufacturer says 27 is the maximum.
I've just installed even a 30T cog (Marchisio make) on my Shimano cassette - just cross-chaining the big ring and the biggest cog is a definite no-no according to my LBS guy.


I could swap out my current crank for the 50-34 AND swap out the cassette for the 13-29 and can keep all the other parts of old?
Yes, I did that on my first roadie.