is ok to have a relay turn on other multiple relays? if so is there a rule about switching the ground or vc are there other unknown issues that a novice may be aware off?
Some relays have a built in diode and are polarized, check your relay diagram, usually on the relay box, to see if there is a diode shown.
As for switching in the way that you describe, it depends on your application/use. If this is a one-off hobby project, I see no problem doing this. If this is an industrial application, I suggest checking with your local electrical authority/engineer for specifics. I have worked for companies as an electrician where the only requirements was results, and as long as there was no danger to humans or equipment, anything that would get the job done was allowed. However, some industrial environments, and I have worked these as well, have rules and guidelines in place.
Hope this helps...