Equivalent sequence/stepper relay to "FINDER - 20.21.9.012.4000"
Q1: Yes, it does say Un = 12V DC, Coil resistance R = 27Ω, and Consumption I at UN = 440mA

So, yes if you wanted to drive 16 relays at the same time it wouyld need 16 * 440mA = 7.04A

Q2: "Minimum/Maximum impulse duration: 0.1s/1h (according to EN 60669)"
i.e. it must be triggered for at least 0.1 seconds, minimum

Q3: Are you asking a question about an alternative part, or a "shopping question"?
That is off-topic. See the Help Centre to understand why.