Re: How employable are you if you have failed an Inital IR once or twice?
If you pass it first time, then naturally you might advertise the fact on your CV. If you didn't, it's probably not worth mentioning the fact.
An application form might ask the question, you must obviously tell the truth.
You might or might not be asked about your IR in an interview. I wouldn't get too worried because even if they do, there's a pretty good chance that pilot interviewing you failed or partialled it, and anyway (s)he will know just how little lapse of concentration can spoilt that particular flight.
For the record, I partialled my IRT on the NDB, and it did nothing to hold me back in my airline career.
What I'm saying it's probably not a show stopper.