1- Not a problem. Maybe just check out moz guide on internal linking for best practices.
2- No. That puts you a manual review away from disappearing.
3- A one page site can work, done correctly. If you are only targeting a couple keywords I could see it making sense. However, it would be pretty hard to rank for "landscaper", "landscaping", "landscape design", "lawn care", etc... You would need an amazing link graph, old domain, tons of citations, steady stream of reviews- and maybe you could rank well for 10 keywords. If you are going to do just one page- do it really well. The effective ones I have seen were long pages, with a great flow, nice graphics, periodic calls to action, and most importantly, they told a story. If you only get one page take 3-4 sentences to say what you do and spend the rest of the time telling your story. Who are you? Why do you do what you do? It should be the best "About" page in your market with a couple fantastic graphics and compelling forms/calls to action.
If you are a niche provider who can tell a story- then go for it. Posted via Mobile Device
Much thanks! I think I'll do number 1, but keep the current design. What Tony stated about how good it looks on mobile devices is the main reason (FYI, I never even considered this aspect because I am a technology grouch and don't have any such devices). I looked at MOZ--good advice. Pertaining to number 3, what do you mean by "tons of citations"? Me citing/linking to other relevant topics on other sites, or vice versa?