You cannot live with your fiance legally; she has to be your wife otherwise ur opening yourself to some serious problems. there are ways to get around this, but im not in the business of giving advice on how to do things the wrong way

as for your wife and employment; here's the wonderful part about the UAE: if she is a 'single' female, she must be sponsored by her employer. However, if she is married, then she can be sponsored by her husband; this is GREAT because it allows her to work anywhere she wants, she'll be a better candidate for companies because now they dont have to pay for her visa fees, and she can quit a job and move on to something else that pays better whenever she wants because the employment ban will not be applicable to her.
One last note: when you sign a term-limited contract (2 years, or 1 year, or max of 3 years) as opposed to the open-ended contract (which renews every 3 years); you put urself at risk. If, for whatever reason, you and your employer are not getting along well, or there are problems in the school, or anything that forces you to resign, you may be legally required to pay damages to the school, to the tune of whatever months' salaries u have left on your contract (so if you hve 6 months left on your 2 year contract, you may be liable to pay back 6 months salaries).
Try to negotiate an open-ended contract.