AE farms do drop salvage, if you choose regular rewards rather than tickets. With the current price of recipes and influence/ticket rates for AE missions, ticket farming is vastly inferior to regular rewards anyway so I don’t know why you’d be ticket farming.
If you were going to do this build with purples, what would the benefit be over what you have now? Would you just be able to stack a bit more recharge and maybe some other resists? Fire/Time is going to be the next character I build and I can afford to do purples/superiors/etc so I'm curious if you think it would be a noticeable improvement.