I have a lot of trees and it is difficult to get things establishes sometimes. A good muck/compost mulch and watering til things are established helps
yes, it's a eucalyptus, one of a huge number of species. I don't know which one that is
yes, me too Hosta.
large trees have large roots and have no respect for boundaries. They will spread way beyond the canopy in some cases. They look like tree/shrub roots to me
some kind of euphorbia, E. peplus maybe. I think most gardeners class that as a weed
the top one is a willowherb, very pretty, I have some, food plant for the Elephant Hawkmoth caterpillar.
Most people class those as weeds.
The other looks like a potentilla, not one of the weedy ones.
I have 4 Sorbus aria, though not 'Lutescens' One is crispy, the rest are not. I've seen this before with trees at this time of year and so far they're all recovered.
I can't see how it would harm anything. You could tip it on soil rather than leaves then it definitely wouldn't. I wash up in the sink, no bowl, but then it goes to the septic tank so it's still available to plants in that area