1. Needs ?
2. Grammatically correct, but we just don't say it that way: "too recently ago" = not long enough ago
3. The second choice explains the situation better.
4. I would say "from the start of season 4". 'as of' is o.kl
5. 'Turn' would indicate at least a 45° change in direction; 'bend' would be less, probably, and most definitely more gradual.