Q: Watashi-wa Koko-ni Sumimasu (「わたしはここにすみます。」).

Is this a good translation of “I live here.” ?

A: “NO!”

 If you meant to say, “I live here (Actually, you have lived there for a long time as a resident.),” you should have said, “Watashi-wa Koko-ni Sundeimasu (-teimasu pattern).” “Watashi-wa Koko-ni Sumimasu (「わたしはここにすみます。」).” is used in the situation like… You are driving around with your realtor, looking for a house. You finally found a right one and tell your decision to your realtor.

 “I like this house. I will live here.” –> “Kono Ie-ga Kiniirimasita. Koko-ni Sumimasu. 「このいえがきにいりました。ここにすみます。」”

 “I live here.” –> “Watashi-wa Koko-ni Sundeimasu. 「わたしはここにすんでいます。」”