I have no clue what you are asking? IMO when the house designed by your architect take advantage of the slope to allow the view without removing any more trees than are neccessary .As for rules in your srea I am pretty sure your architect can find that out.

The problem is, we are not trying to build right away so before we buy the property we want to make sure we can top/cut some of the trees to get the view

As I said the design of the house will decide what trees need to go and there is only one way to find out and that is ask the couty usually an unincorporated lot has less issues but I do not live where you do. Are these lots somehow in an HOA which seems to be the norm in the US

Call the County Clerk and ask who to ask.

If anyone is curious :-), got a call back from county, they go by what ever geotechs recommend. No special restrictions for taking down the trees or slope usage.