In many cases, installing new drywall will boost your home value. Replacing old, damaged, cracked, or wavy drywall is a great way to improve the look and feel of your home, as new drywall installed by a professional shouldn’t have any imperfections. Additionally, removing old drywall means you’ll have open walls, so you can install new insulation and address exposed issues with plumbing and electrical systems running behind the walls. All of these fixes will also add to your home’s value.

To maintain plaster walls, inspect them regularly for cracks and seal them early. Clean the walls by dusting regularly or using a gentle, damp cloth. It's also important to avoid moisture exposure. Repainting as needed will help maintain the wall's appearance and longevity.

Whether you need a drywall anchor depends on the specifics of your project, particularly what you're hanging and where. You do not need a drywall anchor if you can screw or nail the object directly into a wooden stud, as the wood provides sufficient support and stability. However, if there are no studs in the location where you plan to hang the item, you should use drywall anchors to ensure it is securely supported. For very lightweight objects, like small pictures, adhesive picture hanging strips can be a suitable alternative to anchors.

You can technically just paint over hairline cracks in plaster since these cracks are often harmless, but this will mostly be a waste of paint. Paint will only hide the hairline crack for a few months before it shows up again. The best solution is to repair the crack with flexible filler or joint compound before repainting.