Yes, this would help greatly when you're building a system out of a couple "Deploy to Railway" services. Instead of having to manually recreate them.

Also, just copy the service, moving seems way too much in a single step and just keeping it as 2 separate steps of "copy to another project" and then "delete service" makes most sense.

If it's not too much, copying of whole groups of services would be amazing.

Some ideas on how to handle conflics:
Environment variables that the service(s) is using would be copied over. If there are conflicting custom shared variables, the user would be warned and could drop the incoming one or rename one of them (which would rename it in any services that use it)
If there are no matching environments between projects. Ask the user how to map environments from source -> destination.
There are no new environments created in the destination project, only the env variables from matched/mapped environments get carried over.
Naming can be simply indexed, shouldn't cause scope issues since variables are mapped to the id of the service which they reference.