1. We choose поехать cause it means future tense. In English it sounds as “ he will not be able to go...” if to use ездить in English it will sound as he can’t go home permanently 2. Here it is better to choose «приехал» in the meaning of time action, in English it sounds as “he arrived in the end of August, and if we choose “приезжал” it means something like that he used to COME a couple of times