Squats and Deadlifts won’t ruin your V-Taper. They’re just going to make you look huge.
Your genetics are what makes you look like a big block or a big V. So when you hit your 700lb Deadlift you’ll either look like Mariusz (blocky) or Arnold (V-Taper).
If you start buying big pants because you’ve been gaining weight from Squats and Deadlifts it’s probably not because your obliques are getting super thick. It’s because your ass has grown, your legs have grown, and your pelvis might have grown a little bit as well.
Work up to 15 sets of 15 pull-ups with 45 seconds of rest in between each set. You will not need to worry about ruining your V-Taper if you can do that.