I'm about to start HYP I (I'm following the Eternal Beginner routine) and have seen great improvements to now---down 16 lbs, and down about 5% body fat (to around 17% or so). My only problem is spending money on new pants.

I'm currently eating on a small deficit (target loss about 1lb / week) and track it daily as accurately as I can. I also maintain a 40/40/30 carb/protein/fat ratio every day and have been since about half way through FL I. When I start HYP I I'm planning on shifting to a slight caloric surplus (maybe an extra 250-500 per day). I've got a couple of questions:
1. How many extra calories per day is a good target? Obviously I know I'll have to tune this, but I figured I'd ask someone who has done it to see if they had a ballpark figure that worked for them. Should I alter my carb/protein/fat ratio slightly away from fat and split it between the other two?
2. In order for me to track my progress I need to understand when I'm not eating enough, or am eating too much. Along those lines, what should I expect my body fat percentage to do during hypertrophy? In an ideal world all the calories would go toward muscle, but of course that's not what happens. I know I'm going to gain fat as well, but the goal would be to gain more muscle than fat as a ratio, i.e. my body fat percentage continues to go down as I gain weight. I'm curious what others experienced.
Thanks!