I think you completely misunderstand what a "right" is.
Most of the time, the back of that renewal notice tells you how to appeal the nonrenewal notice with your state insurance commissioner - so you'd probably want to do that.
You know, because they sent you that notice, that they are NOT going to renew your policy, at this time. You need to ask your agent, if they'd be willing to stay on the policy IF you get the trees trimmed and the roof problem corrected.
The only one who REALLY knows what's going on, is your agent. Sometimes, an insurance company will use things like this as an 'excuse' to get off of a policy that they don't want to stay on. I've seen this happen, for things like low credit score, or low value homes (under $100,000), or protection class 9 or 10 properties (very rural), or even if your particular agent has a bad loss ratio, and the company is trying to drive him off their books.
So you definately need to put a second call in to your agent - and a call in to a roofer, and to a tree trimmer, to correct these issues.