Recently I saw that on the forums when people asked “how to make a fantasy map on OSM”, other people answered them “do it in JOSM, but dont post it". I don’t have a PC, so I would like to do this in this app.
I understand that this is not what osm is for, but I really like how everything is arranged here.
Why do I need this? I really liked OSM and it would be nice to see something in this style, I saw the project OGF(opengeofiction) But I want something personal and private.
And if it’s possible, how can I see the cards I created in OsmAnd~ or others?
I am ready for any answers, even disappointing ones 
Thank you!
It is literally no different in Vespucci than in JOSM.
As a safety precaution even if you are not running your own instance of the Rails Port, you should add a custom API entry. Probably you would want to change the data styling to something that works better as a map than the current editing centric styles, but that is completely possible.
Yes, but I’m not ready to sell a kidney to a dedicated server for Rails Port. No different from JOSM? This is already interesting, I will try to use this knowledge.
You can easily run it on a laptop in a VM or Docker (don’t forget that you would have nearly no data, which is what makes larger install painful).
Verpucci can read/write to .osm files. Maybe one file will be enough for you. Or you can split your map into different files.
Sale of body parts is unlikely to be required
Assuming you’re using Vespucci for editing, you just need something capable of rendering a very small .osm file. Even the “traditional” switch2osm raster tile approach is unlikely to cost more than 5 Euro a month to do that.
For other options, look elsewhere on this site for an IE language map using BackBlaze’s free tier for storage. Also, various OSM Americana posts emphasis how much (or how little) various bits cost.