My start was your current situation. I started at 222 and am currently at 185, I’m aiming for 15% body fat which for me would be around 170. So I think your numbers are reasonable.
There are formulas out there for estimating lean body weight. At 5’9” and a muscular build my estimate is my lean mass is around 145.
Your goal weight can be whatever weight you feel happy at. 10% body fat is a great goal! But it will be a lot of hard work.
Again there’s no set number. For some folks it’s reaching a previous weight, a certain loss amount, based on BMI or another scale, etc. But no, I wouldn’t trust anything sans a DEXA scan or similar medicinal test to accurately tell you.
Only if you want to. Note that lean body mass can change too.
So I’m not quite at my goal yet, I actually had to adjust it a few times! I was 280 when I started IF, but 312 further back. I finally settled on just aiming for slight middle of BMI and nice round number. But I plan to switch gears and put on more muscle, so that number has never been that important.