Well, if you really want to play the ELF, its time to leave your comfort zone. Realize that this amp only provides 200 Watt. So a 1/4" - speaker out is enough. Some bass amps with a lot more power use it. So why always flaming about that?
If you prefer other amps, and they do have speakon connectors, this is absolutely OK.
I know that the electric light was not invented by improving wax candles. But most people are OK with 1/4" plugs, an old and proven way to connect amps and cabs.
There is no problem. You can daisy-chain two cabs with parallel in/out. In this case the cabs will be work in parallel mode. I don't know a single cab with a in/out, that is not wired in parallel.