I like rimless tanks because there are no visible frame lines other than glass against glass.
Looking at your pictures, it seems like you added some kind of tape to hide the joining of the glass at each end, IMO, it looks like it has a rim.
I don't like the upper trim, but that is my personal opinion, I like "true" rimless tanks, and I have never noticed the "excessive light spillage." I think that rimless tanks like ADA are beautiful.
As far as calcium build up, you can clean the rim weekly to avoid the build up, it doesn't seem like a difficult chore to maintain the beauty of the tank.
Keep in mind that the tank you are building is for your enjoyment, go with what you like, not what others like. The opinions and ideas you get from feedback are there to help you improve your design, but in the end, it is you who is going to look at it every day, and if it isn't what you like, you will never be happy with it.
BTW, I like picture two, sans trim!
Good luck!
E