When I installed Toad, I chose the full install rather than the read only install. I thought that this would be something that I could later change should I decide to. After reading here in the forums, it would appear that one cannot change this after installation (but re-installation is always an option). I would liek to suggest that the read-only mode be expanded to a per-connection basis, or to allow for users the capability to switch between the modes. To make it extra secure for IT folks, there could also be a forced Read-only mode on installation in which the user cannot change from Read-only mode.
I use Toad to connect to two databases. One of them is read only and the other is full read/write. Therefore I chose the full install. For me, having a read-only option in the connection manager would work out perfectly. I wouldn’t be surprised if there are others out there who are in the same situation.