Hi Jazib, in response to your questions:
1. you will need to travel to your nearest Estonian embassy to apply for the D visa.
2. Decisions as to what constitutes sufficient legal income will be made on a case-by-case basis based on the proof of income you submit. The amount of sufficient funds for applying for a digital nomad visa is €116.80 per day. As the DNV can be issued up to 12 months we obviously do not expect a digital nomad to have that money when submitting the application. We expect that a person should have financial means for at least the first month, i.e. €3504 (or €116.80 x 30 days). The amount of the previous income that is sufficient is based on the €116.80 per day / €3504 per month benchmark. Using this we can estimate whether you are able to fulfil the requirement of sufficient financial means in coming months.
3. a. You don't need a visa to buy property in Estonia. Please be reminded of the fact that any visa (including the DNV) is not designed as a way toward permanent relocation to Estonia because in essence these visas are temporary.
b. In Estonia (and EU), the maximum period of stay of a foreigner on a long-stay visa shall not be longer than 548 days within 730 consecutive days. Therefore, if you apply for a DNV for the maximum period of 1 year, after that you can apply for a second DNV for a maximum period of six months. These would be two separate applications and decisions and, if you are successful in both, two separate stay visas. After staying in Estonia for 1,5 years you will be required to leave Estonia. Please note that staying in Estonia on a DNV has no advantage with regards to gaining any form of residence permit in Estonia.