1) Don’t worry about companies with the same or a similar name if they are in a completely different market space, like Chinese restaurants.
2) I’m not sure why you would want two separate names, which would just dilute your brand. As long as everything you do is about landscape design, for your own clients or as a subcontractor for other firms, it seems like it would make more sense to align it all under one brand, which of course can have different capabilities. It’s hard enough to get one brand name well known — two just makes it much more difficult.
3) Build a website, make sure it has a blog, and then start blogging regularly about everything that interests you related to landscape design and to your local community, geography, New Zealand, etc, along with other topics that interest you. Get your brand out there, and interact with others who may one day be your employers or clients. Become known for something in your industry.
4) I think Red Tree Dragon Fly is too long, too many names. Don’t try to be everything in the name.
5) No one will likely get Mskten. I thought at first you were making a play on “Mistaken,” which I thought was interesting, but that would be Mstken or Mstkn, so I’m not sure what you were getting at.