gate camping is possible... even if they are using instas, it is easy to counter, you can either have a interdictor pilot (new type of ship, it is a tech 2 varient of a destroyer) pop an interdiction sphere aka pop a bubble that lasts 4 mins and will either A if someone just came through that gate will be inside the bubble because its a 20km radius and they cant warp unless they get out of it or if they are warping to the gate where the bubble is at they are pulled to the outside edge of the bubble

or the 2nd option is to use a mobile warp bubble that you have to anchor and carry around takes 1 min to anchor... the best option is with a dictor pilot as this is best for mobile gangs/fleets which we are

and like you said or you can scramble them if you see the gate fire and wait for them to move outta the 30 sec gate cloak timer if they are in a slow ship otherwise if its an interceptor or shuttle they will be gone before you can even get a lock