Is it possible while using the Ruby version manager to run scripts not from the console but using other ways — at system startup or by a keyboard shortcut for example?
It'd help to know the system, but the answer is yes, though you'd need to either know which is the current directory, or set the system ruby to be the one you needed for these scripts (especially startup). You might also need to experiment, as it would depend at which point in the startup you needed the scripts to run, but you can probably get more answers on that from the irc rvm channel.