1. "Are basenjis really screamers when they are left alone?"
They can be. Many don't scream at all. Mine does. Or did rather. When I got her as a puppy we diligently tried to crate train her. We put her in her crate and left her knowing she'd cry the first couple nights. What I did not expect was the NOISE that came from that darling little puppy. It was the most shrill, God-awful noise I've ever heard. It was a cross between a seagull and a lady being murdered. Literally. And it was amazing how LOUD it was. Maybe close to putting your ear next to schreeching/screaming brakes on a train? Makes my teeth hurt to think about it. Anyways- I am a patient and determined parent. But I could not tolerate it after the 7th night in a row of CONSTANT screaming. And I mean CONSTANT - as in screamed ALL night. The entire time. No stopping. No tiring herself out and falling asleep like you'd expect to finally happen. I mean, THE ENTIRE night. From then on out she slept in the bed. And was fine. She won. Sometimes you have to pick your battles. I've found that with my Basenji, it's a REAL relationship, so very human. It's like you talk without words and you come to resolutions and comprimises. She now sleeps in the closet on her bed, but will always try to sneak in our bed during the night- funny she always comes to my side (because I will let her in and hubby won't). Back to the question- that's the only time mine has ever screamed.
2. "Are they stupid? I have read over and over they are intelligent dogs and I know they do what they want when they want but I read an article a couple days ago that said the are the 3 dumbest dog."
It depends on your definition of intelligence. Any Basenji owner will of course tell you how brilliant they are. Because, well, they are. But many people want a dog that is obedient. And often they confuse obedience with intelligence. Basenji's are very independent and somewhat self-serving. So long as you know that and can use that to your benefit (treat training), you'll be fine. It's almost a game of wits. I swear my dog can read my thoughts. She knows all sorts of tricks and is very keen on hand signals and body language. We play hide and seek all the time. I hide and she seeks. It's hilarious. Basenji's are very curious and eager to figure things out. They are not usually content to just lie on the floor like most dogs. If you do not provide entertainment or healthy outlets, they will get themselves into fun/trouble.
3. "How are they really with cats? Some say they will always have conflicts but just yesterday I saw a posted picture of a basenji and a kitty sleeping together."
Basenji's are sight and scent hounds; therefore if they see a critter flee, they will pursue and chase. Most cats run from dogs. The bottom line is that you have to have cat-savvy dogs and dog-savvy cats. They can learn to live in harmony if they were raised that way. Mine was not raised with cats. Anytime we visit my parents, she is SO curious of theirs. She ends up getting swatted on the nose and the cat usually ends up under the bed.
Hope that helps. You came to the right place for support!