You'd be fine. You may require some proof of residence when you reach the UK and start using it (eg long-term visa in your passport, rental agreement, etc).
I have used at least a dozen of them over the past 20 years and only on 2 occasions ever been asked for ID of any sort.
Last time was a few years ago when a rather rude VT guard demanded my passport. Not that a passport provides any proof of residency but it seemed to satisfy her in that case, had I shown her my UK passport I imagine further discussion would have ensued.
A space for a passport number is provided on the folder the pass comes in and it is in the T&C that proof of residency can be requested, exactly what form that would be or how it could be proved/dis-proved is another matter.
Are these things so cheap compared to an ALR that it is worth entering into an arrangement for office or personal space overseas?
Could well be, although not legally valid unless you are resident outside of GB.
ALR 7 day £478 std £724 1st
Britrail 8 day consecutive £210 std £310 1st
8 day in 1 month £265 std £390 1st
(Approx cost in £ based on € passes)
And there is the advantage of there being no restriction on pre-10am London IC services.
I can see how it would be tempting for anyone with access to a non-UK address through relatives or friends to use one.
Even for commuting they could be a great deal.
Assuming 240 working days, to cover commuting anywhere in the former NSE area would cost approx £4500, considerably cheaper than a season for many journeys.
I can't imagine it would go un-noticed if a commuter was using one daily though.
To the OP: Bring a bill of some sort with your name and UAE address on it as proof, it is very unlikely you will be asked for any but if anyone had a problem beyond that then it would very much be up to them to prove it.
Oh and if you get a flexi-pass beware of on-train staff trying to punch, scribble on, incorrectly date or otherwise deface them. This is a much more likely scenario than being asked for ID and I have had all sorts of stupid attempts in the past, the worst was a guard who using a fat felt tip marker checked the ticket by putting a black line straight through one of the unused date boxes. After that I made a plastic sleeve to protect the pass from wear and tear as well as dopey rail staff.