is there anything in the document used to create the easement in regards to allowed use, maintenance, or anything else?
removing the cattle guard is almost assuredly improper. Can you prove they removed it? What are your damages due to the removal?
as to ditches; is there some reason they want ditches or more importantly, need ditches? While you say the road is clear and passable, I can get a lot of places in some pretty rotten roads and as such, would have to consider them clear and passable. What is the real condition of the road? Is it rutted and pocked?
I am not an attorney and any advice is not to be construed as legal advice. You might even want to ignore my advice. Actually, there are plenty of real attorneys that you might want to ignore as well.