Can you identify these plants please?

Ive found these growing in my first attempt at a border this year.  I'm pretty sure the first 2 are the same one just a big version then some little versions of the same thing. 

Number 3 looked nice enough but thr flower is starting to fade now. 

Number 4 has sprang up next to some wild bluebells which I didn't want to move but I'm not sure if I'm cultivating a weed or not as it wouldn't be the first time. 

Many help greatly appreciated.  Also can you let me know if they are things I should keep, dig out or will flower in summer etc?