There is an increased risk of falls amongst elderly patients who take benzodiazepines,
but there is also an increased risk amongst sleep-deprived patients.
Elderly patients are often also sensitive to medications and require a lower dose than is the norm.
Temazepam is a fairly short-acting benzo so once-daily dosing doesn't carry the same risk of physical dependence as taking diazepam once a day, for example, although over time it is possible to build up a residual background level.
The main concern is psychological dependence and rebound insomnia on stopping the drug. - a procedure which should be gradual.
There is also the possibility of it becoming less effective over time - but, equally, some people can take a steady benzo dose for years for sleep; 'mileage' can vary. Sleep has a large psychological component and this can affect the efficacy of sleeping tablets.
Sleep hygiene is important. This means going to bed at a set time, using bed only for sleeping in, doing relaxing activities before bed (not involving a screen), no caffeine after midday, no nicotine right before bed, getting up after 30-60 minutes of not sleeping and doing something else for 10 minutes, not lying in no matter how bad the night's sleep was... it can take a while to get into good habits but they can really help.
I'll see if I can find some papers on temazepam use in the elderly later - or you can try a google scholar search."