Its usefulness as a laptop replacement may be limited. Remember it’s a locked down read-only version of Linux. The steam deck uses an a/b model to update. Basically there are two separate versions of the OS on the machine - when it updates it replaces one copy and makes that the default, and uses the other as the backup. Next system update it replaces the other copy and switches to that. It switches back and forth that way, putting a stock image on with each update. So you’d probably want to go down the route of running your own OS on it.
Without that it does limit a little in how useful it is as a laptop like device. It depends what you want to do on it of course, and your Flatpak apps and personal files will stay but any other customisation you do to the device will get wiped each time it does a major update. That would include any installed software outside the Flatpak route if you unlock Pacman.
It seems like a capable machine though. I have mine hooked up to my TV at 4K when at home. I use it to stream 4K game content from my desktop to my living room, but I’ve also played with the desktop mode in 4k and it’s been good. It renders 4k video well, and we know it’s capable of playing video games at 720p directly which is still generally intensive.
I can’t see why it wouldn’t be able to do basic graphics work, but no idea about more intensive work like 3D modelling and video encoding.
Personally I’d get a dedicated device for work but if you can’t afford that or you dont want to carry more than one device around then I guess it’s worth a try?
Just remember if you do use it for work that also entails setting it up to back up your personal data. Your game data is largely backed up by Steam but if you put your work stuff on there then you’ll need to be protecting yourself in case of damage or theft.
I don’t understand? You can download Dosbox and Dosbox-X in desktop mode and add them to Steam like other apps. Why do you need a website?