Pruning + planting question

Hi everyone! I have several questions. I’m a new gardener so apologies if it’s dumb. 1. Can I trim these roses down further to the pink line? It use to be up to the red and I snipped it back, but I want it even smaller and tighter next season, so would trimming it to the pink help? It is getting woody there though. 2. I’ve never done anything to the lavender plant and it’s grown massive. I’d like to trim it down a bit to the pink lines, is that ok? And also, how do I get the bare bits circled in red to grow flowers? It looks pretty dead/stick-like to be honest but it’s street facing. 3. I planted this teddy bear magnolia but the ground had so much clay. Is it going to do ok or should I take it out again and try to remove some clay. Clay isn’t mixed into the soil, but to dig a deep enough hole I drilled into the clay and it got mixed in on the top when planted it. My garden only has about 20-30cm of dirt before it becomes solid rock hard clay that I can’t work with.