OK, Good work! You've started to tell us 4 or 5 of the answers to the long list of questions from Tolak up there and its good you're trying to read carefully!
We still don't know the test kit type, so we don't know whether to trust the numbers yet.
If the 0.1 trace of ammonia is correct, that confirms we're still in a "Fish-In Cycling Situation", which we'd expect. So we'd not want to be adding to our problems with more fish, but that's happened, so we'll have to live with it I guess! Or perhaps the filter is mostly cycled and the fish additions have just caused what we call a "mini-cycle" but I doubt it. Instead I'm worried this is still a "pre-cycling" situation and lots of water will still need to be changed.
Yes, the Tiger Barbs will pretty much run the tank ragged. That's what we call a "stocking consideration", stocking choices involving firstly how much the tank can handle, secondly what size groupings work for individual species and thirdly, how the various choices in the stocking plan might or might not work with the other species in the plan.
~~waterdrop~~