1) Absolutely wrong. Apogee and range don't work out that way. While generally speaking higher apogees equals longer range, its certainly possible to have a high apogee with shorter range. This is commonly employed with short-range missiles in order to greatly increase terminal velocity (and make interception more difficult).And 692km apogee correlates to very long ranges (5,000km to 6,000km) So no way shaheen-3 has that
Lol there Is no Missile in the world that can Launch MIRV at this range Due to Atmospheric Pressure
2) The discernable atmosphere ends at about 100 KM (Karman Line). Getting any missile beyond 300-500 KM (max) without leaving the atmosphere is impossible. Thermal effects would burn up any RV at the speeds needed tp get to such ranges.