Border Renovation & Plant ID

I am working slowly through my inherited garden tidying things up. I still have a small section of border which is a couple of metres wide that I haven't yet touched or paid attention to. I was looking at at this morning as you do before going to work and realised it's a prime piece of border as it's south facing so could have some interesting things planted, either already or by me soon!
As you can see from picture 1 it's a little uncared for and has been left to its own devices for some years. It has a few small trees growing which I will dig out this weekend. They appear too seed in many places from some sort of plum type tree I have.

Any suggestions about tackling some of this. I don't really want to completely dig it all out as there are clearly plants here as pics below show, I just don't know what they are and have yet to experience the garden in spring or summer. In picture 2 below, is this a good plant to keep, or should I do anything with it?

In picture 3 I have this plant that looks a little like a nettle but I'm hoping grows into something pretty. Many ideas or advice?

Now picture 4, I'm guessing this is a weed! Is it one of the bad ones

And finally another interesting looking red/green plant mixed in with other things. Can this be identified and is it a keeper?
Any advice/guidance would be very much appreciated.

Posts
First and last look like hardy geraniums. The second last one is that weed that sticks to you.
Hi DYL, that will keep you busy
Pic 2 is a hardy geranium, probably a pink one
in pic 3, the pink flowers are red deadnettle and there's another member of the same family there, might be white deadnettle.
4 i can see chick weed, goose grass and ground ivy, prolific seeders but easy to remove
5 looks like another hardy geranium but not the same one.
Be careful when you start clearing, you may find bits of other, more interesting, stuff.
In the sticks near Peterborough
Number two looks like a buttercup masquerading as a geranium, I once nurtured one for weeks thinking it was a geranium before the horror sprouted buttercups.
Number two could be lamium but I think it's just nettle.
Number three weed is the same one I get plentifully every year, it pulls up pretty easily but you have to keep on top of it.
No idea what number 4 is but I think it looks suspiciously like a weed.
It's fun seeing what comes up though
We must have been typing at the exact same time nutcutlet
It's the stems of the first one that give it away as a geranium to me. I think it's probably G. endressii.
and the second look like lamiums, L album, and in flower Lamium purpureum.
white and red dead nettle.
There's a very easy test for nettle
In the sticks near Peterborough
I studied the photos and enlarged them by clicking on them, thought of my answer, but nutcutlet got there first! Not much more to say, but does the geranium pic 5 have a strong smell? I see it's an early flowerer, could be Geranium macrorrhizum, good in shade and difficult places.
Yes, interesting!
DYD
You mention a you have some kind of plum tree which is the source of the saplings. Plums and Damsons are prone to suckering and these plantsmay actually be suckers from the tree.
Hi Invicta, I just Googled and the tree is indeed Damson.
These particular saplings are probably 10m away from the main Damson tree trunk so I guess they have sprouted up on their own? Not sure how far the roots spread.
I expect they will be difficult to dig out then if they are suckers!