To answer a couple of the "am I normal" questions -
You should see their incoming missiles (ASM or AMM, either ones) but that's what the Res 1 sensor is for, as people have been saying. Be warned, though - getting decent range on a res 1 sensor at low techs means that the bugger could end up pretty big. Probably too big to throw on each of your escorts without massing it out of where you want it to be. One solution is to make a dedicated sensor ship. Have a couple spares, though, because active sensor ships are target number 1 for the other guys.
Other solution to the massive Res 1 issue is to cut down the range some. 6.7m km is quite far out to start intercepting the other guy's missiles, particularly if you are at low tech levels like you say, but Zook mentioned that one already.
Regarding seeing the other guy's AMMs that are picking apart your ASMs - Nope. You shouldn't see those. If you see the other guy's AMMs doing PD for his fleet, then either a) yer too close, or b) yer res 1 sensor is WAY too powerful.
1 more thing - correct me if I'm wrong, but it looks like you're using civilian engines in those ships. IIRC, standard power for an Ion Mil in about 60, and for a civ is 150. True, the civ engine gives more power, but weighs a lot more. You could put in mil 5 engines (I think) for the same weight as 1 civ engine, and get double the power. You'll have higher fuel consumption too, of course. Maybe that's what you were going for, in which case, nevermind. But mass is usually at a premium on ships, particularly low tech where things are bulkier, and fuel's not an issue. Even if it were, the ranges for those ships are pretty freakin' huge. 50 bil is good enough for local-to-mid range defensive fleets.