Not sure on the synodontis or bn plec.
Pearls are very pretty, good choice!
Drawing a blank right now on what kinds of other fish you could get, rather tired today, but do you not like harlequin rasboras?
If you can get rid of the danios, that would probably be best. They are temperate fish rather than tropical.
Also while they are quite small, they're very active, so most people would like to see them in a 4ft tank.
The pics are really hard to tell. It's best, if you can, to look at them in natural lighting. I can barely make heads or tails of my own tests, let alone others pics

Hopefully someone else with better eyes can help you with that.
Sorry I really can't be of much help, but I look forward to seeing everything when it's all set up.
