Possible Clues:

• Public garden isn't finished on Trim site produced by upstart
• Newcomer's music upset audience finally leaving concert hall, say
• One who has recently risen to wealth, notice or power
• Upstart after a year runs meeting-place briefly
• Johnny-come-lately, upstart
• One's blown away by mad Peruvian climber
• Nouveau riche location second to be struck off, substandard
• Newly visible item? That's standard with planet (Sun's beginning to disappear)
• Level ground -- not base for climber?
• Drug dropped in normal place for someone not yet accepted