Return to Belgium as a retired US-Belgian citizen

I am dual US-Belgian citizen considering returning to Belgium to retire.  I have worked in the US mainly and i am looking for advice from people who went through the same process re:

-Belgian registration and administrative formalities

-Belgian and US tax obligations when returning

-US retirement accounts pensions, investments and bank accounts

-reinstate belgian health insurance and social security

-moving personal belongings and transfer financial assets (pension)

-recommendations for accountants or tax advisors who understand both countries

are there any good forums or checklists for this ?

thank you for any advice.  Am just starting looking into this.