I understand it is a free for all right now for testing right away but I would like to explain why a limited access mechanic would really make the IC experience so much better for PVP and PVE.
First, both these mechanic were in place in DAOC, Darkness Falls was controlled by one faction winning on the War map. The Labrynth was always open to all 3 sides. Most players will tell you that the Darkness Falls experience was just much superior.
Right now in IC with all 3 sides going in its chaotic and really hard to accomplish anything. While i know some people like this, I think most would want it to be a little more controlled and thats what happens when 1 alliance controls it or atleast cuts off access to 1 enemy side. The big 3way chaotic fights can still happen but just not very often. When 1 sides controls the IC and clears out the enemy zerg, now you can actually accomplish your PVE or do your farming for stones with much more safety. You will still have to watch your back for enemy lurkers but there wont be an enemy zerg and you will have a window to get stuff accomplished. This is also a time that the Pure PVE players from that alliance can actually come to IC because they wont when its a 24/7 gankfest. I am not saying this should be required for PVE players but it is a time that would actually bring them to the IC.
I'd like to run you threw why the Darkness Fall (DF) experience was so great in DAOC with its limited access to one Alliance. When your alliance doesn't always have access to something, it makes it much more special when you do. It makes its exciting and can also even change your plans for the night. When an alliance gained control of DF it first created a MAD RUSH, this was exciting, your side rushed in to CLEAR out the enemy. This was a very fun PVP experience and could last up to an hour. After that you could now do the things you needed to do inside (craft) (stones)(bosses). if you just wanted to PVP you would go back outside to the alliance war. For those thats stayed inside you did what you needed to do knowing your time was limited and while also watching your back because there was still always a few enemies inside. Then when you did see the BIG message that your side lost control it was a big WARNING and also a PANIC. For IC this is teh perfect time to go the vault and bank stones. This was also when your side would fall back to a spot and make your LAST STAND. This was always an epic fight.
For these reasons I hope we atl east see a mechanic where IC access requires you to hold your home keeps + 1 enemy keep.