first looks like

Erigeron karvinskianus

it self seeds qite a bit, I cant grow it on my heavy loam

2) some Weigela?

portrait from Missouri botanical garden

3) Delosperma or similar

4) oxalis

Last one is an Oxalis. There are lots of pale pink species. I find it hard to believe you haven't come across Weigela at home. It's a ubiquitous common shrub in much of the US. There are a couple of cultivars which bicolored flowers.

This is the Erigeron in my garden taken today. You can see that it likes to grow in stonework so Linaria's heavy soil would definitely not suit it.. It grows in cracks in the pavement outside my house.

Thanks! Looked up the weigela, delosperma, and oxalis and it seems like weigela coraeensis and oxalis corymbosa and delosperma cooperi. I didn’t know the erygeon and delosperma weren’t native but they were growing all over the place.

Floral, looks like I posted at the same time you did as I didn’t see your comment before. I’ve definitely seen weigela but they are all weigela florida where I am but I’ve never seen this particular species. And yes, I didn’t take pics but there was a wall of the erigeon all growing in cracks of the bricks. It was definitely fascinating especially with the different colors. I like how yours is growing on the wall of the stairs, looks very natural, like a historical English garden.