If the things she does now bother you, be prepared to accept that marriage won't improve them. It may, but you can't depend on that.

Sometimes once people get married, they let themselves go because, well, they can. Sometimes they thrive on the support of another person.

My DH has developed some pretty severe health issues, both physical and mental, but not until more than 20 years into the marriage. Yeah, you deal with what you have to deal with, but I think it's easier to start off on a good foot, kwim? If she's committed to doing better, then that's great. If she's only doing it to please you, then after the wedding, you have the chance of it going either way.

In a nutshell, your concerns may be a huge red flag. It's probably better addressed them fully before any long term commitment.