What do mean by stretching? You can either set your display to a 4:3 resolution, if it supports it, or play the game in windowed mode with a 4:3 resolution.
The layout doesn't work very well with narrow window widths, or on mobile screens. It's only comfortable to use if you expand the window to at least a 1080p window width, so it's not very useful on a desktop using tiling window management.
If you need to develop and link to system libraries with the Flatpak version of VS Code, you will need to install openssh-server on the system, and then using the Remote SSH extension. Then you can SSH from the sandbox to the host system. Alternative, you can develop software using any platform and without relying on system libraries with VS Code Dev Containers with Docker/Podman. Finally, it is possible to use nix-shell as a development environment as an alternative to Docker/Podman.
Personally, I use the Remote SSH extension so that I can use my laptop to develop code that's maintained and compiled by my desktop. That way my laptop can focus purely on rendering the UI and reducing energy consumption. Also justifies keeping the desktop on throughout the day. If not for developing things specifically for Pop, I'd use nix-shell for setting up development environments.
Chromium is better served through third parties like Vivaldi. Or by Chrome from Google. Most of which offer debs. We recommend Firefox though.