Hi chimichanga
Have flown into ALA a few times and may be able to offer a little help. As stated ATC will offer you the option of a QFE or QNH approach. We always elect to go for the QNH approach with cross checking of cleared altitude in metres versus altitude in feet via a company generated metric conversion block. The stated QFE you gave of 933Hpa is very low but if you add the threshold elevation millibar correction from the approach plate which I think is 79mb then this gives you a working QNH of 1012. When ATC clear you to, for example, GELKI you are cleared to 1600m on QNH. Off our conversion table this cleared altitude corresponds to 5200ft (the plate gives 5180ft) and then further descent is down to 1300m which is 4300ft. This is all double checked and confirmed by both crew members before descending. We also have a metric conversion pb which is selected on below Transition and can be used to cross check. High terrain, high elevation airfield and high temperatures make this field challenging and when you throw into the mix the weather ( summer BIG cb's and in winter 75m FZFG and temperatures well south of freezing) its not one to be treated lightly. ATC overall do a pretty good job and I've never had any problems.
Hope this is of assistance.