Too far away. Temperate climate deciduous trees have dormancy requirements, to grow these in the tropics you must be in a location that experiences the minimum number of chilling hours for the particular kind of tree. With many orchard fruit tree cultivars these hours are actually known and listed by nursery catalogs and other sources; I don't remember seeing these reported for any ornamental trees.

OK I'll give it a go. This can be nothing more than the wildest of guesses based on a vague idea of the shape and something about the way the topmost branches are held. Maybe Wych Elm - Ulmus glabra. But they could be almost any of the deciduous trees found in the Carpathians ie oak, linden, hornbeam, etc. There are several different species mixed in there, I believe. I'm curious as to why you want to know if they'll grow in Australia. The picture comes from Wiki and shows a house in Transylvania i.e. the Carpathian Mountains. Check the climate there and compare with Eastern States of Oz. I suspect there's not much similarity.

well, I don't know if these closeups will help more. The leaves are alternate. There are ovate as well as lobed, mostly closer to the inner part of the stem. The stem is thornless. It's clean, healthy foliage, both of which do not seem like hawthorn or ash traits. So a very good specimen of whatever it is. Flipping through Dirr drawings, I would say Hawthorn over Sorbus. None of the Hawthorn leaf shapes he shows are dead on, but close and he does say there tons of Hawthorn species and a lot of variability. If it is the one-seeded hawthorn, are the berries too immature now to open and look? Are sorbus berries one-seeded also?

Salix sp., some kind of willow