Financing the investment allowed for investments in bonds and shares is definitely not recommended. The Bulgarian government is looking with suspicion at any applications who use financing and may reject the application. I definitely don't recommend the financed option.
In a brief summary, regarding your questions, are the following answers. There are certain consecutive steps to obtain Bulgarian citizenship-by-investment. First is obtaining a long-stay visa type “D” (not needed for EU citizens). Second is receiving a permanent residency after an initial investment (depending on the investment and complying with the Bulgarian legislation). Third is obtaining Bulgarian citizenship (after additional investment, depending on the initial investment). According to the Bulgarian legislation, such an investment for receiving a permanent residency can be: investment over 1 million Bulgarian lev by acquiring: shares of Bulgarian companies traded on a Bulgarian regulated market; bonds and treasury bills, issued by the state or the municipalities with a residual term to maturity less than six months; ownership of a separate part of the property of a Bulgarian company with more than 50 percent state or municipal participation in the capital; shares in a company, owned by the state or municipalities; Bulgarian intellectual property (trademarks, utility models, patents, etc.); rights under concession contracts on the territory of the republic of Bulgaria. Second is investment over 1 million lev at a licensed credit institution in Bulgaria, under a contract for trust management with a term of not less than five years. Third is investment at priority investment projects certified by the ministry of the economy according to the Bulgarian legislation. (the investment is between 1 million and 10 million lev). Furthermore, for obtaining Bulgarian citizenship for point one and point two, not less than one year after the granted permanent residency, the person should increase the investment by an additional investment under the same terms of the law, to a value of at least 2 million lev. For point three, the investment must be maintained above the minimum limit (2 million lev), which is determined by the ministry of the economy. The total period for obtaining Bulgarian citizenship in the abovementioned procedure is about two years, and the investment in bonds and treasury bills, issued by the state or the municipalities, can be determined as the most secure.
Here follows some actual information about getting Bulgarian residency based on investments: One million Bulgarian lev into an investment is enough to apply for permanent residency. Acquiring citizenship demands first to have a permanent residence on that reason, and second, after one year to improve the investment with no less than 1 million lev. Regarding the applicant's relatives, family members of a foreigner are the persons who live with him / her in one household and are: spouse; children of the alien and of his / her spouse, including the adopted, who have not reached the age of 18 and have not been married; the children, including the adopted ones, of the alien who have not reached the age of 18 and have not been married when he or she has the parental rights and the children are dependent on him/her; children, including those adopted, of the spouse who have not reached the age of 18 and are not married when he or she has custody and the children are dependent on him/her. Family members are the children of 18 years of age of the alien or of his/her spouse who has not been married when serious health reasons require personal care for them or for such reasons are objectively unable to provide their own support. After the receiving of the permanent residency statute of the applicant, the family members mentioned above could apply on that reason for long-term residency statute. The spouse, and the minors and juveniles who have not entered into a marriage, of the applicant could apply for permanent residency after the applicant receives the same statute first. After receiving the statute of residency, the applicant (in addition at the above mentioned option) and/or the family members could apply for Bulgarian citizenship, if they cover the demands: is of full age (more than 18 years old); for at least five years has been granted a permit for permanent or long-term residence in the republic of Bulgaria; has not been convicted of a premeditated offense of a general nature by a Bulgarian court and has not been prosecuted for such offense, unless rehabilitated; has income or occupation, which gives him/her the opportunity to support himself in the republic of Bulgaria. The time enough for each service depends from legal terms, the speed of following our instructions from the applicant, and sometimes from additional court cases connected with the procedures. Our team has seen results from three months up to four years.