@Lili2022
You "want" it to be active... but what will it do? :-)
1. I think it's the same. You pay social contributions as employed or self-employed (or perhaps unemployed). So your contributions are the same (for the same salary) whether you are employed by a third-party entity, or your own EOOD (well, your employee contribution is the same, but if it's your EOOD then you're paying the employer contribution too). But if you're asking if it's better to have a company, rather than be self-employed, I believe many accountants would say there is more flexibility via your company. Self-employed is maybe simpler, but you have a company already.
2. To pay contributions as an employee of your EOOD, you would need to be receiving a salary. The salary can be paid from the company's revenue, or from the company's capital (the money you invest in it). If no capital and no revenue, then there's no money to pay your salary. :-(
3. I don't think you can associate "any" income with your company. I have some income, but it can't go through your EOOD. :-) If you have professional activity (consulting, remote working, cleaning houses) then, as an employee of the company, you can say that income is the company's (and you will issue a company invoice in relation to it).
4. Interesting question, probably needs an accountant to answer. But I would guess no. If you personally own a property, then income arising from it (as rent) I would expect to be considered your personal income. However, I suppose it might be possible for your EOOD to enter into some kind of "agent" agreement with you so that the company maintains the property and rents it out on whatever basis they chose. However, I'd imagine the company should pay you something from this, which would still be personal income to be declared.
5. Dividends are a declared distribution, based on your annual accounts, and the profits made. No profit made, no dividend possible. But if you make a profit you don't have to issue it all as a dividend. Instead, you can keep some (or all) of it as "retained earnings". This can sit in your bank, or some form of investment account. Or you might invest in productive assets that will make more money for the business (e.g. property to rent, or machinery that can be put to use). You might also prefer to take money out as expenses (which reduces profit and taxes), rather than dividends: maybe a larger salary, or a fancy company car, or private healthcare/pension.
6. Yes. See above (i.e. from capital or revenue, not profit).
7. I can't, sorry, but I'm sure they exist. Perhaps someone else will offer a suggestion. I can recommend (by private message) one (legal/accounting/English) in Plovdiv, and I'd say accounting is fairly geographically flexible, it's not like you need to go see him every day (I suspect most of it can be done remotely).