The most important maintenance task for us London nurseries is also the most important maintenance task for you – watering.
If you aren’t going to be able to water much, choose drought-tolerant trees, and opt for smaller trees that will more quickly establish, so that you only need to water them well for perhaps a couple of months after planting.
Also, if water will be lacking, don’t plant anything under the tree for the first year, because it may compete with water. That means the weeds should be also pulled regularly.
There’s no need to prune a tree when planting it in order to “balance out the canopy with the root ball” or anything like that.
It’s a good idea to remove dead wood and probably damaged wood, and it’s really important to remove potentially problematic branches, such as codominant branches that are both competing to be the leader. That causes major problems down the road, so it should be dealt with when the tree is young.
There’s no benefit wrapping the trunk with burlap or paper, as it doesn’t really protect from climate extremes. Sun scald on the south side of the trunk is usually due to lack of soil moisture, not so much due to exposure to the sun.
If you have rodents, plastic corrugated pipe can be put around the tree in the first year to keep them away. Just cut a slit all the way down the pipe to get it around the tree.