If the opponent has all the door keys then a way must be found to not use the doors.
The 'opponent' has all the keys to their doors. However, their doors are both limited and uninspiring. By participating in this forum, other doors will eventually become discernible, and should you wish to have a look through these doors, they are there, ready and waiting.
The best way to not use their doors is to make a conscious choice not to do so. By doing this, you empower yourself by taking responsibility for your own actions and your own destiny. By starting off with this, you are well on your way to becoming master of your own life.
I don't know how to make a different kind of door.
You really don't have to make different kinds of doors as there are plenty "out there" you can choose to walk through or to have a look at. However, I believe the best way, should you want to do so, to making your own doors is start off really simply by assessing what it is you want and not fall into the trap of becoming the sort of person "others" want you to be - these others include friends, family, community groups, etc. For the most part, these people truly believe they have your best interests at heart...
But someone might find a way.
As mentioned above, there are those who have already done so. However, that is not to say that every possibility has been exhausted - not by a long shot.
I think one of the problems with this sort of information dissemination is the fear that it can readily cause in people. You add this sort of fear on top of every other type 'out there' then we begin to partake of a downward spiral of sorts. There are reasons why this is being encouraged (it is not a natural phenomena at all), and if people want, I can go into this at length elsewhere. However, as far as this thread is concerned, the fear that is generated can readily be neutralised by realising this fear is purposely being generated by those with an agenda. The thing here is that we all have opportunities to choose to either play a part in this fear-mongering, or choose to do otherwise.