I saw at least thirty houses before I bought mine. I saw a handful that had issues like yours as well as another handful that were far worse, I'm sure. The ones with issues like yours? Didn't even consider them. Walked in and got the hell right back out pissed off that someone would lure us in with photos amounting to lies of omission.

As an investor, and every home buyer is, I know that if someone isn't taking care of minor things then they're sure as shit not taking care of the major things like AC/Heat systems, plumbing, roof, electrical etc. I'm not trying to badger you. In fact, I'm only writing this to help. After all, this is /r/HomeImprovement.

You want all potential buyers to feel welcome and comfortable when looking at your home. So, here are some things that are affordable on a budget that you can DIY to get these issues you've listed presentable to potential buyers so that they aren't too distracted or too afraid to consider your house.

1. Fix the stairs man. You can literally have the guys at HD cut your lumber to size if you don't have your own saw. Honestly, even if it doesn't look finished, the repair is $10-$20 at most. But if you don't spend the $10 and the 2 hours measuring then measuring again then running to the store and back to nail them down, there's no way anybody with a brain, a serious buyer I mean, is going to jump over two broken stairs to land on a third stair that may or may not kill them. And, if they're not going up there, they're not going to envision turning that bare naked blank slate of an attic into the most awesome fucking man cave ever. Fix the stairs...

2.1 The green flooring in the mud room... Peel and stick that area, maybe? It's a cheap fix, but they're making peel and stick much more satisfactory these days. Good backing, good adherence, some of it is even nice looking. Used some in an apartment kitchen about ten years ago that I wouldn't put in my house today. But I saw some in my buddy's house a couple months ago and didn't even know it was peel and stick until he told me. Had texture and nice color. Looked like real stone.

2.2 Paint the paneling. Don't go cheap on this paint and don't half ass the following details. After painting 9 hollow core doors in my upstairs last week and my master a few weeks prior, I'm sold on Behr Premium Ultra paint+primer. I'm sitting in my man cave typing this while looking at the wood panel walls I painted over four years ago and, besides that squashed bug that I've left on the wall as a reminder to all the other bugs that think they can just waltz into my house uninvited like they own the place (jk)... (or am I?)....., the walls still look great.

Sand them first. Seriously, don't kill yourself sanding but sand them first. It'll remove dirt and splinters and other things that'll mess up your paint job. Then fill all the thumb tack/nail holes. If you're ambitious you can putty all the signature indented paneling lines. Sand those down smooth and paint. $50 for quality paint and a painting kit is well worth it to make an area like that look and feel so much brighter and inviting.

1. Paint the cabinets. Peel and stick the floors if they're in bad shape. Clean. Clean. Clean. De-clutter then clean again. Refrigerators and appliances are and always have been optional. We didn't marry our wives for their hair color. People don't buy their houses for the Frigidaire. Unless you're in a super high end million dollar market I can't imagine anyone that wouldn't expect you to take that POS with you when you go. But make sure it's clean inside and out while it's there. In fact, that goes for the whole house. Pick a room and focus only on that room until you're finished. Then close it off and open it only to potential buyers/agents. It'll seem like it's taking forever to clean the entire house but once you're done you're going to be so relieved.

2. Get new carpet. If you can't afford to do that, at least hire professional carpet cleaners and invest in a nice rug that'll go under the coffee table. Buyers understand carpet gets old. But if they see that a rug makes all the difference, they know that's an inexpensive remedy until they can buy new carpet. And it won't distract them as long as there aren't any smells. So, again, hire the pros and get the smell good stuff but not the scotch guard. Is twelve year old carpet. Should have been replaced four to six years ago if you haven't vacuumed two to three times per week and steam cleaned professionally at least once or twice a year anyway.

3. Hideous old bathroom? Clean it. If you have to get new matching toilet covers and bath mats/rugs and shower curtain, then do. Maybe change the lighting or something. Airwick and Glade Plugins are wonderful things to have in an old bathroom. I wouldn't do much more than that in there.

Good luck.