RE: Need some advice
It's definately time for a serious chat w/ the landowner. But remember, it is his land and his family. I don't think you have holiday dinners w/ him so tread lightly.
I myself would pleasantly address the safety issues as the main topic and at all times be respectful (don't insult his family member who has appeared). Maybe subtle reminders of how you have and will continue to help out and do your part for the maint. of his property.
You might want to try the approach of getting this guy more involved in the activities on the land so he feels more a part of it - it may lead to him understanding your position a little better. Maybe not.
But just be ready for anything in your situation. I hate to say it - but it could be you who gets walking papers. Older folks pretty much keep family first ya know.