Yes, after you check-in luggage, AA may ask you to put your hand-luggage onto the belt to weigh it.

Notebook bag, they also ask you open to show a notebook inside, but more lenient on the weight provided the stuff inside "looks related", like mouse, adapter, cables, charger,

If other bag, very strict on 7kg.

Females handbag - if big, they also ask to weigh it. e.g. bigger than a pack of pagoda peanuts (large).

It's usual at LCCT KL here. They only open the check-in luggage counter around 30-40 min before gate-open/departure.

Normally, if 7am flight, just reach there 6am.
Else reach there 5:30am, go breakfast, then only check-in luggage at 6-6:20am.
Reach gate by 6:45am still alright. No need kiasu, as all have seating number already, except some idiots who will put their cabin luggage in front and not at their own seat (overhead).