They told you correct. But they didn't tell you everything...
You will need to call in all inspections. In addition to you calling in, the respective sub also needs to call in. Your calling in of a rough in inspection won't schedule an inspector as it's just the first step. All the subs must then call in for Elec, hvac, plumbing, gas, etc in time and for the same day before the inspector will show up.
The sub has a permit in addition to the building permit. He can't call in an inspection on your GC permit and you can't call in for him on his trade permit.
Point is I guess, make sure all subs are ready on the same day and make sure they all call in for the same day as you or you'll be left standing there waiting on an inspector that isn't even scheduled and then have to do it all over again.
Most don't require anyone to be there especially during these early inspections where the structure is reasonably accessible without a key, etc. I would recommend being there though. If you have errands to run or whatever, you can usually request for a phone call 30 minutes prior to them showing up. I've had about 50% success rate with the phone calls; half the time they never call.
If you call in for inspection and talk to the office staff, they will typically tell you if one of your predecessor inspections is still outstanding, like sheathing, venting, subfloor, etc.