You have some good questions, I can answer at least some of the panama ones.
"Why has Panama become so Chinese there is Chinese language newspapers there?"
people Trafficking. they apparently even have their own mafia h ere, presumably for collections of people export payments, among other things. It is apparently a very lucrative business for the chinese govt/military.
"Stronghold for potential military interests in Carribean, Cuba etc., chokehold on Panama Canal. Sorry so random, but these are questions that go begging when thinking about Chinese activities 90 miles off our shore and on our former Canal Zone. Oh, yeah, and they bought up the land where our former Southern Command post was in Panama. Really, what do you think? I'm just a gal from CA."
Which land are you talking about, the place they are dumping containers across from balboa port?
I am not aware of them buying land on quarry heights (i.e. southcom), but even if they did, so what? They don't own the flight lines at howard or albrook, nor the rodman docks (afaik), which are the primary assets when you look at things from that perspective. As far as a bunch of run-down building on quarry heights, they are welcome to them, aside from the bunker, but I do not believe they own any of them.
can you provide a source/cite on southcom post land purchase?
btw I don't disagree that the chinese are playing a macro-chess game, both economic and military. There has, however, been a fair amount of alarmist or simply inaccurate material posting on the web and FR regarding the chinese presence in Panama particularly regarding the ownership/management of the former Panama Canal Commission. I think the game here is primarily economic, though presumably they are playing more than one game.
In the end, with the US financing much of the chinese economic expansion, and china helping to finance our government debt, there isn't much that is going to be done on this front. I do think Panama is clearly still US military sphere of influence, all you have to do is see the number of GI's on the streets here to see that.