You don't "need" opposable thumbs or binocular vision. To be a tool making and using animal certainly doesn't require thumbs. I can pick up a pen and hold it between my fingers without using my thumb (index and pinky under, middle and ring over), and I can use a finger on each hand to oppose one another as well. We have a bias towards what is natural for us, but it's not logical to assume such things are the natural order.
You are certainly wrong about that. The opposable thumb and stereo vision are extremely important. You cannot
make tools and use them without opposable thumbs. Yeah, you can pick up a pen with two fingers. What else can you do? Nothing of importance. Try removing the pen cap, and don't use your teeth (teeth are a opposable system as well). The idea of using the fingers of two hands to do the work of the opposable thumbs on each hand is laughable, seriously. A hand with only index finger and thumb is more useful than a hand without a thumb.
One of the first inventions (way before the wheel) was the knife. Try making and using a knife with hands without thumbs. It doesn't work. You cannot even pick up a piece of sharo stone and use it against another object to cut it without thumbs. Clothing cannot be made without thumbs. Spears cannot be held and thrown without thumbs.
It's not about the thumb perse, it's about the principle. You just need an opposable structure like that to be able to grasp things easily. And that opposable structure needs to be on a flexible armlike something that you can observe. So manipulating stuff with your opposable teeth is out of the question because your head movement is limited, and you cannot see what you do. If it's not opposable fingers, it's perhaps opposable tentacles. And there the human hand is again more efficient than that as well. Everything else is a waste of energy, which is why it is inferior and will over the course of time not result in advanced species.
Same goes for stereo vision. All superior animals have stereo vision. Without stereo vision and depth perception, there is no fine manipulation of things, and no successful hunting (the aforementioned spear throwing). It goes "hand in hand", so to speak.
Some things are certain. Advanced civilizations need to live in a "dry" environment, not in the water. Otherwise you can completely forget electronics. Upright walk, hands, visual and auditory depth perception, etc... are a given. Otherwise you might have simple life, even intelligent life, but not life that can build computers and space ships. A dolphin, no matter how intelligent it will become in the next couple of millions of years, will never, ever, build a house, a computer or a spaceship. NEVER.