Tax and Business Expertise for German Tax Law's and german capital company type

Dear Ladies and Gents, I need a Tax and business expert who can give me advice about the differences in income tax when I have a main job with earnings and I want to get additional earnings outside of work. In general I'm not interested in getting to a setup where I would become a private liable entrepreneur. I only need advice whether it would make more sense in getting earnings outside of work as a private person, and the effects of tax change of my main job income, when I have additional earnings. What are the tax rules for additional earnings as a private person? Or whether it would make more sense when I setup a "Unternehmergesellschaft" which is the smallest german capital company type. I also need to know about the costs which are affecting me when I setup the "Unternehmergesellschaft" and the timeframe for setup to get it through offical anouncement. Also I need to know about the general rules to increase the share capital after setup, and the linked costs which I need to calculate for it. What risks do I need to consider when the "Unternehmergesellschaft" lost all capital? Will I be privately liable in this case? When do I need to highlight that my company is going bancrupt to play according to the rules, and don't get punished for this scenario? Also I need to know about the tax year, whether I can choose the dates freely to pay the tax office, according to the date of setup? And the general aspects I need to consider in cash flow management in relation to the choosen tax year. How I can calculate the expected tax payment upfront, and of course which costs the company can hand in to the tax office to shrink earnings. Are payments for freelancers, software, maybe later on a company car allowed to shrink the earnings? Can I also define and change over time my own personal payment out of the company to work against earnings? Is this allowed, how often can you adapt these properties (private earnings), and which rules and costs are likely to show up when you do it. What do I need to consider when I have the earnings of the main job and also earnings from the company according to german tax law? Can I stay inside statutory health insurance, when I setup the "Unternehmergesellschaft" next to main job? Will the rate for the statutory health insurance change when doing both? Which rules do I need to consider according to german work time law, when doing both things in parallel? Can I use a rented appartement as location of the "Unternehmergesellschaft"? Do I need to get a allowance from my landlord, when I don't need to meet business contacts inside the company office on a regular basis, and also the sound level is not disturbing the other parties inside the multi-family tenement? Could I as a private person rent a part of my rented flat to the company, as office space cost? Is this practice allowed? Do you need to have a offical payment for office space, or could it also be a symbolic value at the beginning? Can you adjust this figure over time with the same space and same cost for me as a private person? Is this allowed? Would it be allowed to ask a private house owner, to setup the companys adress at his house adress when you have a better Business tax rate at this town? What do you need to know about when you hire a freelancer which is located in a different country? Do I don't pay the tax at the foreign country, and I need to pay german tax which is linked with the freelancers payment? Which type of contract do I need to setup when working with a foreign freelancer, to have minimum risk of unexpected costs and a guaranteed result? I know about "Werkvertrag" according to (§ 631 Abs. 1 BGB), but I don't know whether I'm aloud to hire a person outside of germany and still use contract according to german law... Is this possible? What would you advice? Are I'm aloud to hire a freelancer according to "Werkvertrag" when I have no company, basically only as a private person? What are the linked risks?