Does this kill bacteria and germs?

Yes! I discovered this product after watching the episode on shark tank where it took bacteria from chicken and cleaned it better than Lysol.

everyone talks about how good this products cleans,but what about the smell. I need an absolute odor free product

It doesn't have a perfume smell. It has a light smell that is closer to Method's fragrance-free hand soap. It just smells clean. I get asthma attacks and allergic reactions to fragrances and this doesn't trigger it. What little smell it has dissipated quickly. Give it a try by buying a single bottle to see if it works for you. Everyone's sensitivity is different. The light smell may be fine for some of us but not others.

How does it do on concrete, hardwood and large cermaic tile floors? Also had a leak and have fine mildew spots on all surfaces from ceiling down..??

This is more for sanitizing surfaces and cleaning up spills. While I have used it for bathroom cleaning and preventing mold/mildew, I wouldn't recommend it for your question. If you are looking for a natural type cleaner Better Life brand does make a tub and tile cleaner which I used moving into a rental that had mold/mildew in the bathroom. I also used Method brand all purpose wipes on the ceiling for the water drop spots where mold was happening. Our bathroom has a window but no vent so it gets very steamy and wet after a shower and we moved into a moldy space. It took a good bit of scrubbing but it all came out, no chemical burns on skin, no coughing from fumes and the smell wasn't bad. Upkeep is very easy too. I have asthma and so when people would use stuff like Lysol, Windex or other heavy cleaners around me I would have to sit outside. Here though I don't have a problem anymore. Better Life brand also makes a daily shower spray which we use every day after showering to prevent mold. All of the products between Better Life, Method, Mrs Meyers and a few other sustainable companies all make this house built in the 1920s sparkle. Mildew/mold GONE!

According to ewg this cleaner contains methylisothiazolinone. is that right?

3/01/ 2022 Unknown as the ingredient list is incredibly vague. Current ingredient list from the product page is as follows: "Purified water, coconut surfactant, vegetable-based surfactant, pure essential oils of clary sage and lemon, preservative" There is a good chance the mysterious 'preservative' is indeed methylisothiazolinone if it was listed in the past, plus other products of theirs (like their floor cleaner) do contain it unfortunately. I was hoping maybe some of their products were worth buying but unfortunately it seems like they are all greenwashed. :(