1. At any distance you have guys better at a shorter distance and other guys better at a longer distance. Cram had a slow 400m time at around 49seconds, but still ran 1:42
2. Renato Canova has talked numerous times about improving your PB by increasing endurance rather than basic speed
2. El G is clearly better at endurance, his 12:50 5k indicates that he's an endurance guy
3. Maybe he did do 1:42.7 in training. It still isn't going to be his best event to compete at even in a meet. If it isn't a true run or he gets boxed, he'd get smoked. Same reason Kipketer or doesn't need to be getting embarrassed running 400s. In a comparison a slow run 5k he wins nearly ever time, they have to hurt themselves turning up the pace to beat him.
3. In the past pre EPO era we had endurance milers. Moorcroft did a 3:49 mile, a 13:00 5k and a 1:46:6 800m. Kip Keino's 3:33 at altitude is massively impressive and he was racing at 3k/5k/10k so probably wasn't that fast at 800.
I don't know if El G doped. I don't much care, it's either widespread or random guys do it. It doesn't take away from the fact he was one of the hardest workers out there.