Janko, as others have said, you do you. What “most” ostomates do is basically irrelevant until and unless someone's anecdotal report hits you as something that may be helpful to your situation. None of us is identical to another. But we do seem to ask the same kinds of questions, so be reassured that you're in good company.
Your bag question: If you are getting two good days' wear with no hint of any potential leak or damage to the peristomal skin, you might consider trying 3 days' wear. But only if you want to, not because “most” others are doing something differently.
I had been having unpredictable leaks and blowouts in the Hollister 2-piece I was given post-op and in rehab—lasting only between 2 and 42 hours! The Sensura Mio Soft Convex one-piece pouch and the Brava Ostomy Ring saved me! It wasn't until two months after my ileostomy that a wise and wonderful Ostomy Care Nurse suggested it at my first appointment. Apparently, my roly-poly belly with creases was not letting the flat wafer of the other product get a tight seal. In the 12+ months since the change, I've had only one leak.* Both the OCN and the manufacturer say the optimum wear time is 3 days. When I change, I can see that the ring at the bottom of my stomach has eroded and could leak in a short time, so 3 days is good for me! (*After a couple of good months, OCN suggested trying it without the ring. Oops! That was a 2-day wear and a major eruption!)
About odor control: peppermint oil is an economical and moderately effective choice. My OCN recommended it but cautioned me to use only ONE drop. More can interfere with the seal of the wafer and ring, as well as being an irritant to the skin. I prefer the Brava Lubricating Deodorant for its effectiveness and ease of emptying. However, Medicare limits how many bottles I may have in a four-month period and, trust me, their decision is not based on real experience with ileostomies that need frequent emptying! I now use the Brava only at bedtime or when I might need to empty away from home because I can empty without rinsing. At other times, I use either the peppermint oil or M9 drops. Both control odor, but rinsing the bag is necessary.
With my apologies for blathering on, I hope there's at least a kernel of help in my reply. Come back often and do let us hear what you decide is your best practice for caring for your ostomy!