Indeed this is all about trying to elevate China's prestige and presence and sticking to the Americans is a bonus, I just question the actual feasability of this...sure the Chi-Com's can throw lots of money and manpower at this and however long it takes to do they could do it...
From a cost/benefit standpoint I find it much easier and cheaper to simply co-opt the Panamanian's and take outright control of the existing canal...and even if it came to force, what would the current bed-wetter in Das Kapital do to threaten a principle bond holder? Not much I would bet.
So on those points I say this is all a pipedream...