Cramped Carpeted Disaster

This bathroom has lots of room, but for some reason the builder didn't use the given space wisely. Our double sink vanity is snuggled into a corner which makes it difficult for my husband and I to use it at the same time. The cabinet doors don't shut well or without force (so we usually just leave them open. Our shower is very small, for one person, and is also very old. It has begun to rust around the door and is also difficult to shut. This leads to the carpet issue...who puts carpet in a bathroom? Around our shower door are visible large mold stains. We also have a door that leads to our back porch that has brought in a lot of carpet stains. Last but not least, our tub is another problem. Whether it was designed for a child or Gary Coleman it is very very small. I am about 5 foot three and I can't stretch out in it...my husband is 6 feet tall so he has even more trouble. My husband I are newlyweds and we are working to make our nice house a home. We have a plan for what we would like to see in our bathroom but we would need major help.