ᐅ Splash guard for the facade and transition from lawn to flower bed

Hello dear friends,
I am interested in how you have solved the following issues:

1: We initially planned to create flower beds along some of the house’s exterior walls. We like the idea of not just seeing the bare facade in the garden but also some greenery there.
However, we have been advised to lay gravel along the facade to act as a splash guard, preventing strong rain from splashing dirt onto the walls. That sounds reasonable at first.
But we really don’t like gravel. Bark mulch could be an alternative. Are there other ways to create flower beds next to exterior walls while still preventing heavy rain from making everything dirty?

2: Along the edges of the property, we want to install a privacy screen. Currently, Siberian larch is our preferred choice. We also want to create flower beds along the privacy screen so that, over the years as everything grows, we can enjoy “green walls.”
We don’t want to make the beds straight and parallel to the screen but rather slightly curved, with rounded corners to create a more natural look.
Initially, to avoid classic lawn edging stones, we considered using a lawn edging strip, as it is less visually intrusive.
However, we were advised to use stones after all because we plan to use a robotic lawn mower. With the strip, it would always leave a strip of uncut grass along the edge, whereas with stones, the mower can pass over them and no strip remains. This sounds logical.
Does anyone have experience or know of alternatives to classic stones that don’t cause this uncut strip problem?