It looks like you're still in the early parts of the cycle. The only thing you should be doing is waiting for ammonia and nitrite to be undetectable...
I don't recommend adding any bacteria. It's a waste of money unless you have some rush...or you're the guys from that show "Tanked". All the bacteria you need is already on your live rock.
Don't add any fish. Why put them through the stress of elevated ammonia. We don't think much about it but elevated ammonia and nitrite is terrible for fish blood. Kills leukocytes and turns it brown. Just wait it out. You already have a silverside in there...
Well its hard to say. If you're using all live rock and live sand. Not long at all. If everything is sterile...about a month. You didn't tell us much about your tank setup.
Due to living upstairs I'm limited to a 20 gallon.... So I have a 20 gallon tall with a glass holes overflow box into a 10 gallon sump. I've got 30 pounds of pink Fiji live fine sand and approx 15 pounds of live rock and 15 pounds of dry rock from reef rocks... I've got a 24" 4 bulb t5 HO light fixture ... Nothing special
Since it's not all live rock, maybe 3 weeks...maybe less? Just keep testing every few days...don't run your foam fractionator during this time. It will only slow the process. As soon as your nitrates start to rise you can turn on the fractionator and add "hardy" fish.