If you are sure you existing policy covers you for the duration of your stay, it is not necessary to have health cover in Thailand, many choose to self insure instead. The cover against a visa only applies to an OA visa where no funds are required here as the visa is issued in your home country
Suggest you learn some Thai and travel for 1st year. Every province is different, pattaya or Jomtien has bad reputation BUT I don't drink and have great life here. Easy to get involved with sport, golf, sailing, charity work and then make friends with good hearted and business ladies