I have had this plant for 2-3 years now and recently (about 2 months ago) I started noticing some problems on the leaves such as dry spots, bumps and brown near the edges and base. What can I do about this? I water the plant about once every 5-8 days, it gets plenty of light (as you can see from the pics). I have never fertilized the plant and I also dust it off about every 2 weeks.
I think your yucca plant looks fine, for a houseplant. If you have such a plant for 2-3 years in your home, it will look more or less like yours.
I cannot see exactly what you mean with the bumps and brown spots. The brown at the base (stem) is normal, it is because the stem under it is brown. You can tear off some of the lower leaves (pull down at the stem), the plant will look better then (because the lower leaves droop/hang very much). But best time to do this is spring though, just before growing season starts (now it is a bit late in growing season and it is coming to an end soon).
You say that you never fertilize it, well that might be one cause of a bit yellowing leaves. I give my Yuccas some liquid fertilizer (Pokon) every 2-3- weeks during the spring and summer. Furthermore, the plant will be happy when you repot it every 2-3 years, in a slightly larger container with fresh potting soil. Also you water it quite often, it would be better to water it every two weeks or so, and wait until the upper part of the soil is dry (half finger deep). Brown tips of the leaves are often a sign of too much water (but you have no picture of that).