Howard H
In answer to your points I'd comment as follows: -
1. The issue of people missing flights has been blown up out of proportion. There were some problems at the start of the summer season but now, when queues do build up there is now much more active management of them including staff identifying and prioritising passengers on flights approaching boarding time.
2. Check in generally opens two hours before departure which should be plenty of time. Also, as more and more people check in on line this part of the process will be increasingly by-passed at the airport
3. Peel are investing £12m in a new, larger security search area which should be ready by next summer. This also includes moving pretty much all the shops airside to help encourage more of them to spend before they fly...!