Hey @joaoseixas93!
There are a couple of other threads open for these points so I’m going to link them below and then the convo can continue - let us know if you have any more questions or don’t feel like these threads covered what you were looking for 
- We’ve talked a bit about a forecasting feature here.
- A web version is on our roadmap
- If you change the category of something, Emma should learn from this and then apply transactions to that new category. There is a little more info here.
- We’ve talked about how to deal with annual or rare expenses here which might help with your last point.
Thank you 