Try uninstalling and then re-installing said app - be forewarned though that most RAM boosters / memory cleaners are absolutely redundant in Android. Due to the nature of pre-loading your most used apps in order to give them better latency, there's little to no point of running these memory cleaners. In fact, by running them, you lose a bit of your battery as the OS has to run the processor to select and pre-load other apps.
Yes - moving an app to the SD card usually prevents it from starting up at boot - this is also why widgets or apps that have some sort of notification / reminder / push message need to remain in internal memory.
You can run a script (if you're rooted) or you can use an app like Tasker / Llama to run an app depending on a particular set of conditions.