Thinking about doing an "immortal" playthrough. Need some advice.

I'm starting a game as the Duke of Brittany in 867 and used Ruler Designer to get my health to ~60. Based on another post I'm sure we've all seen on the official forums, that should hopefully allow me to survive until 1453 provided that I keep a good spymaster and I avoid leading armies.

My problem is that I had to take a bunch of very negative traits to get my health so high, so everyone automatically has -100 opinion with me. So what I did is swear fealty to West Francia (for now), and imprisoned and banished all of my Count-level vassals. I figured since everyone hated me anyway, there's no point in trying to avoid some temporary tyranny.

After about 100-200 years, the long reign opinion bonus will really start to kick in and override all of the penalties that I have. So my goal is to just survive to that point, and then I can start expanding very easily since all my vassals will love me. My problem now is that because everyone in my own court hates me, including my councillors, I'm sure that I will be very susceptible to murder plots. All of my skills are 0 so I am pretty much defenseless. I'm thinking about just banishing everyone in my court (no family, no councillors, no nothing), except I need to keep a spymaster to protect myself against plots from outside my court.

Can anyone think of a way where I can constantly keep relations high with just 1 person, even when I have so many negative modifiers?