I've come up with a primary product idea, and the first prototypes have been made and are being tested by trusted friends in my industry. I work for a company who is willing to buy the finished product from me and market/sell it as a distributor, and there is already precedent for employees having exactly this relationship with my employer, where they make things "off the clock" and sell them to the company for distribution.

My main concerns are:

1. Liability - I don't want to get sued and lose my house. I plan to make my business an LLC to help with this.
2. Privacy - I would rather not have my personal address out there for anyone to find if they decide they don't like my product. I've heard that paying a company to be my registered agent can help with this, but I don't know how easy/safe/expensive this is.
3. Financial sustainability - I don't want to lock myself into really expensive overhead issues by having other companies handle administrative tasks (like getting my tax ID and filing my LLC application) that are easy enough for me to do myself, however -
4. Time investment sustainability - I don't want to spend so much time chasing down paperwork issues that I come to hate/not have time for making my products.
5. Keeping options open - I'm not sure at this stage if I will end up continuing to make these products myself long-term, or if I will eventually try to sell the product design to a third party. I already have a third party in mind, and I think I have a good chance of getting them on board if I choose to. I've assumed that I'll need to patent my product to have even a chance of selling the idea later, but -
6. Patents - they're expensive! Or so I've heard. Is it really that bad, and do I have to deal with a lawyer? Are there lower cost resources that won't end up stealing my idea or giving me a pittance in exchange for it? I'm new and dumb and exactly the kind of first-timer that I can imagine getting a lump-sum that feels very high, only to find that I undervalued my product. Or, on the other hand, I could over-value the idea to the point that I foolishly turn down a good offer and never get it sold.

I also plan to make additional products that don't pertain to my industry in the same way, which I might sell on etsy or something. I've done this a bit before, and it went just fine. This is just the first time that I've had the potential to make enough money to matter for tax purposes, and the first time that I'm selling a tool that costs enough and could be distributed widely enough for there to be an increased chance of someone becoming upset if they break something with it and try to sue me or some such nonsense.