I recall that the last time CPT was discussed, there was a dispute over bunks, which would suggest that they were looking at a multiple crew. They may well be looking at a single crew operation, but I'd expect IALPA to shoot this down pretty quickly.
DM has already said that long haul is the way to go for EI and somehow I doubt he will be unrealistic enough to press this issue. 12h for a single crew is really not on; I certainly wouldn't want to be on such a flight. And what happens if there needs to be a diversion? Isn't JNB the diversion airport - which would mean, potentially, another two hours tagged onto that.
As for new metal, EI is said to be looking closely at options and the word on the street (so to speak) is that Boeing has offered 777s and 787-900s. Airbus's latest offering, the 350, really doesn't seem to have made any headway with EI; I've heard several rumours about EI's fleet plans, but all surround Boeing aircraft - 777s only, 777/787 etc, but never anything about the A350. Remember, of course, that on the Atlantic routes, a decision on open skies could come pretty quickly and if EI needed to get new aircraft, it would be very difficult to get 332s at short notice, so whichever manufacturer can provide the aircraft EI needs in a short timescale will have a very good chance of getting the EI deal. No doubt Boeing, spurred by recent successes at AI, AC (yes, I know, tiny problem there), QF (by all accounts, imminent) and aware of EI's growth potential, will want to make sure it's seen as EI's partner in that growth.