... on a side note, do exchange traded option spreads exist? Exchange traded futures spreads are great, so I'm wondering if they exist for options?
Options are often traded in multiple legs aka spreads, but if you mean options on different underlyings/instruments then I don't think so, although it's possible that exchanges are working on this or already have something I don't know about.
However, such orders are supported by Interactive Brokers, as their system allows creating virtual instruments that may consist of different options. In the past I tried to use that method to arbitrage options on multiple underlyings, but those orders never went through. I'm assuming IB would need to fill each leg separately and the system simply waits forever for the ask price on the whole combo to be below my bid. Though there are some software companies that specialize in order execution and may be able to fill complex orders with different legs through different exchanges, so some algo funds may be doing just that.