The recovery is alive and well. Absent any major disasters (the scariest prospect is China at the moment) things will continue to improve: http://www.imf.org/external/pubs/ft/weo/2014/update/01/
Brazil at 2.7% of global GDP is insufficient both in size to cause major problems outside Latin America.
No offense, I don't even know where to begin with this rubbish. First of all, the lack of references/sources for their data and projections lends very little credibility to the analysis. The hyperbolic projection of future debt growth is highly dubious, especially considering much of the developed world has been deleveraging over the past 5 years (excluding Canada, Australia, Norway, and a few other nations that have had sustained credit growth over the crisis). Basically this website makes huge unfounded claims and is devoid of any credibility. The internet is an amazing tool for research, but it is also cesspool of misinformation and nonsense, this website falls into that category.
America does have a precarious situation in terms of un-funded future liabilities (referring to medicare and medicaid, etc), but nothing that cannot be resolved. Those liabilities are simply accounting projections based on current taxation, demographics, and spending requirements. All three of those variables can be negotiated in congress, it's called fiscal policy, social spending, and immigration policy.
As for the dollar, considering we use dollars to purchase every single good and service produced in the USA, I really doubt that the dollar is due to collapse anytime soon. The probability that the world suddenly decides it no longer wants to purchase Iphones, windows/mac computers, levis jeans, google search for advertising, goldman sachs/jpmorgan for corporate advisory, kraft/heinz foods, education top universities, etc etc etc, is a mathematical impossibility (to use the words of your website).
The value of a currency is the extent to which foreign nations purchase the goods and services from the nation that issues the currency. Nothing else.