Majorly bad idea!! If you do that make sure you can still teach the JAA/EASA PPL course on return to the uk. A lot of the US courses only teach you how to fly the lessons as opposed to here in the uk where you are taught HOW to teach. In all honesty though i wouldn't even consider an FI course unless there is a job waiting for you. As somebody has already touched upon, don't go gambling now the odds are not just against you, in your position, they are fixed in favour of the house.
If you are able to get a weekend job instructing whilst working mon-fri in the call centre that would be ace, keeping current (getting paid for it) and saving up cash to revalidate the rest of your licences.
Get your IR renewed and just do it in a sim if that's possible as its cheaper, unless you need to ME/IR in which case just go in for the test and wing it mate! Not as hard as the initial.