It may sound icky, but yes, urine encourages microbial activity that breaks down organic matter faster. It’s rich in nitrogen, which helps balance carbon-heavy materials like dry leaves or straw. Use sparingly and apply it to a well-balanced pile, not one already high in nitrogen. 

Typically, the best type to trim bushes is when they’re dormant. Winter and late fall, potentially even early spring are the best times to trim your bushes. These seasons allow you better access to the branches, as all leaves are gone and the branches are more brittle, making the trimming process easier. 

For minor unevenness, you don't necessarily need to remove grass before leveling. You can apply a topdressing mixture to fill in low areas and even out the surface. However, for more significant unevenness or deep depressions, it might be necessary to temporarily remove the grass to ensure proper leveling and soil compaction. After filling and leveling, you can replace the grass or consider reseeding the area.

Debris removal is often included in the overall cost of having a tree removed from your property. However, tree maintenance service companies do not always include debris removal in their pricing, so ask any contractors offering tree trimming cost estimates whether or not removal is included. If you want to keep the wood mulch, ask if they charge extra for it as well.