Help for a total beginner.

I would recommend consulting with someone before committing too much in your current design. Might be able to steer you to lower cost, more sustainable solutions.

Ratchet and Pawls for instance are sourceable items, and if you can design around the various configurations available in the marketplace, then your design will be of lower cost without custom machined components.

Does a gas spring need to be attached within a plastic and/or resin box? There are probably other options that could eliminate the need for an inserted plastic mount. All good questions for a design review and consultation.

1&2: You can get some free models here by looking at the "Product Detail" of different parts. I wouldn't buy them from McMaster, but hopefully it can point you in the right direction.

Example: https://www.mcmaster.com/ratchet-gears/

6. SolidWorks is generally purchased third party. Here is a Link to a pervious question with some good answers and other options:

https://grabcad.com/questions/what-is-the-best-3d-cad-software-for-home-use-that-wont-break-the-bank

5: There are so many now. I hear Enders are good, Prusas have been around for ages, 3 years ago I got a MonoPrice Ultimate for $500 and it's a bit finicky, but it's always come through in the end. My Dad bought an out of the box Dermal DigiLab for $700 and it's a treat, Plug and play. They do kind of force you to buy "their filament" and use "their software", and it only prints PLA, though you can get around most that with some ingenuity. At work we had a $6000 piece-of-tar that I couldn't get to work, and a $200 second-hand Flash Forge that just kept kicking out prototypes with no issues. The ten inch length of box number 2 is going to be the kicker. If you can split that into two parts that are under 200 mm (~7-3/4 inches), it'll really open up the printers you can use. These are all FDM's. I think that would work for you as long as there aren't any really small parts ones. I find 0.120-0.075 is the thinnest wall I can have and still some decent strength out of it and making “pegs” is a pain.

4. You can always ask the community for help; it sounds like Martin is interested. If you want to be a bit more hands on, I would look around to your local community. Where I lived, in a town of 6,000 people in the middle-of-no-where-Wyoming, we still have a Maker Space. It costs $10 a day or a monthly membership of $30 (this might be a bit cheaper than ones in your area). They are generally really easy to work with, have the computers and printers setup and might have an "instructor" (high school/college student) to help, or maybe just hire to do the models and print.
Example site: https://powellmakerspace.org/membership/
Or, if you think it's a good marketable and complex design and you're crunched for personal time. I would reach out to a local school (high school or college) and ask it they need cap stone projects. At MSU they need around 50 a year for the ME/MET's. You get a team of 4-6 six student that will do the design process for you, you get to keep your product, and you can set a budget for manufacturing. and the product should get vetted. It will take a full year to get the product back, but you might get a lot of free work out of some kids.
Example site: https://www.montana.edu/mie/me/capstone/index.html

Again, look around in your area, you might be surprised how much help there is.

Sorry for the Book. Hopefully you can read around my spelling errors enough to find this useful.

Franko,

If your idea is patentable, or even if it is not but still a good money making venture for you, it would be a good idea to draw up a Non-Disclosure Agreement (NDA) with anyone you may choose to work with. I really liked Thomas' answer with the idea of getting a college program involved - this sounds like a real win-win idea!

Thank you all so much for your input. I have been an engineer and tech executive since 1983. The largest global group I ran was about 700 people globally and the largest annual budget of $100M.
First about NDA's. They mean absolutely nothing. In nearly 40 years of business experience in the technology world, I would say I dealt with 1000's of NDA. I once fired one of our lawyers because he kept on insisting on having an NDA with a vendor I wanted to do business with and the lawyer was holding us up because of NDA. So why do Billionair owners of major companies allow for large departments of generally junior lawyers who work strictly on NDAs. The Billioaires don't have time to attend to every detail that goes on in their company. They have a general counsel who in many cases makes millions of dollars per year, and the general counsel thinks that the more lawyers on his/her staff the better. Okay, that was just some brotherly advice on NDAs. I did get a copy of Solid Works last night (free for personal use). As I expected it's like Adobe Premiere Pro .Try to use it to make a picture montage for a party. It will take about a year. I played with Solid Works for about an hour. My goal was to draw a cube, put dimensions on it an perhaps get it ready to go to a mold maker to send to an injection molding company to make me 1,000,000 cubes. I was not successful. I may buy a cheap printer for now and utilize one of the simple CAD software just to play around.
The couple parts that I need like a ratchet gear and Pawl have to be custom made. It will take to long to explain. So I would love to use the services of someone like Martin. I will decide on overall housing later because that will reveal what the product is. Oh by the way in many cases the patent doesn't mean anything either. The industry giants will challenge your patent and bankrupt you with legal fees because you don't have as many legal dollars as they do.
As for how to house the gas springs and so on,I have done a decent amount of research and talked to knowledgeable vendors. I believe the design will work. I think most of you are engineers. You don't want to get stuck with Analysis Paralysis. I built the world's largest private network from a design literally off the back of a napkin (I still have the Napkin) and when the industries biggest vendor , CISCO, told me I am doing it wrong, I told them to go to h$ll. When they went to my boss (One of the richest men in the world) to complain, he told them I hired Franko to build the network go talk to him. The back of the napkin design today, almost two decades later, is still pretty much runs unchanged and is now the design standard used by the the entire financial services world. Point being, you don't always have to do it the way others did.

Martin, my email address is frankrahimi@rocketmail.com