Working on a non-magical character who has 4 arms and who I want to use flaming swords. I would prefer the swords to be magical so that I don't have to replace any kind of fuel, as well as being able to turn the flames on and off when needed.
Are there rules for such a thing, and if so where?
4th ed. in case it matters
Actual flames? Not happening. Magic? Also not happening. But you can get a Custom Look on the blades to give them an AR 'skin' of being on fire while drawn.
As for why there aren't magic items that work for mundanes, just remember that magic in SR is different from magic in D&D. In D&D, if you make a +1 Rapier, then it is a +1 Rapier, no matter who holds it. But in SR, magic flows from the energy of living things. Enchanting an object allows someone awakened to direct the flow through that object, shaping it in new ways, like putting a sprayer head on a hose. Without being hooked up to the hose (the mage), the sprayer (the focus) is useless.
Magic that works for mundanes is one of those holy grails of magical R&D, to the point that there's even a major bequest in Big D's will about it.