You can use the same doorknobs throughout a house if that's your preference - cabinet hardware does not need to match doors from room to room. Like Anglo, I have different door hardware in the bathrooms than elsewhere. What metal are your current door hinges and will you worry about them matching your doorknobs? I'm not suggesting they have to match - depending on the room, mine do not - but if you're worried about matching cabinet hardware this would probably occur to you at some point as well so better to think about it now.

Which irritates you the most -- the way the yard looks or the way the house looks? You could begin by doing any grading your yard needs and adding any concrete or gravel or pavers for your driveway and sidewalk and any retaining walls; then plant grass where you're going to want grass. Then stop work on the outside and finish the work on the inside, beginning with the indoor project that will require the most ripping out and replacing of any electrical and plumbing and heat/ac duct/vents. All that core replacement work needs to be completed before beginning any finishing work. Once you're through with all the tearing out, you can install any new flooring. Then you can get to the finishing touches such as paint and then light fixtures. Then get back to the outdoor tasks of patio, flower garden, etc.

We also bought a house a couple years ago that have these doors.... but they are painted white. If yours were solid wood I would not paint but since they aren't, painting will update the look ... a little. I think you need to live in the home for awhile before committing to changes that cost a lot. My concern is that if you change to the shaker doors you like you would also have to change all the door trim and floor molding to a simpler look to match. The cost could snowball especially if you can't diy and have to pay someone to do everything. Even painting is a major cost if you aren't doing it yourself. Is it your forever home? It could be worth your time and money to change if you plan on staying here awhile. But if it is a long time home you also have time to make changes in stages you can prioritize. Our home IS our forever home. I'm not crazy about a lot of things but changing the doors are far down the list of things I want to change. First is kitchen appliances, changing flooring and hopefully someday changing our master closet/bath. I hate the layout but at this point don't know how to make it better. Because of that it is the only place in our house that hasn't been repainted. But my husband tackles a lot of our home projects. Time and money.

To figure out a whole home palette you start with what must stay (budget restraints)/ what will stay (you like it). Second step is to determine the colors you love. If you love the fall burnt oranges and greens you will want very different neutrals and whites to complement your art, furnishings and accessories than you would want if you love charcoal and lime green or peach and cornflower blue. You pick your neutrals and whites to complement the things that must stay/will stay and the colors you love. Trim does not need to be white or wood. Ceilings can also be white, the same color as the walls or an accent color. Most people do white or wood trim and white ceilings because that is what they think it should be, but there really aren't any rules that say you can't do something different.