Having a personal account in a local bank may be a data point if you want to make a case about where you should be taxed but it won't automatically make you have permanent establishment or tax resident in Estonia
Yeah, highly recommend that. You can also contact Estonian folks who do understand the idea of running a co in Estonia and living elsewhere which isn't common in a country like Germany as local accountants there may be confused, there's a bunch of people on this list that have gone through at least some govt vetting https://e-resident.gov.ee/marketplace/service-providers/
I personally had a good working relationship with 1Office in particular and recommend them (wasn't a client but they were a partner when I worked for the e-Residency program and a buddy's GF works there who I trust and who does good work)
Yeah I should definitely check with an accountant in the country where I will end up residing.